AM335x: Beaglebone stops to boot with current git kernel

AM335x: Beaglebone stops to boot with current git kernel

[Igor Mazanov]

Hello,

Beaglebone boot process is broken with the current git kernel. I use 
omap2plus_defconfig for tests.

It looks like the boot process stops due to the last changes in the AM33xx clock 
sysbsystem. A following patch resolves this issue:

diff --git a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c 
b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
index ad8d43b..858e180 100644
--- a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
+++ b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
@@ -586,7 +586,7 @@ static struct omap_hwmod am33xx_smartreflex0_hwmod = {
         .class          = &am33xx_smartreflex_hwmod_class,
         .clkdm_name     = "l4_wkup_clkdm",
         .mpu_irqs       = am33xx_smartreflex0_irqs,
-       .main_clk       = "smartreflex0_fck",
+       .main_clk       = "smartreflex_mpu_fck",
         .prcm           = {
                 .omap4  = {
                         .clkctrl_offs   = 
AM33XX_CM_WKUP_SMARTREFLEX0_CLKCTRL_OFFSET,
@@ -606,7 +606,7 @@ static struct omap_hwmod am33xx_smartreflex1_hwmod = {
         .class          = &am33xx_smartreflex_hwmod_class,
         .clkdm_name     = "l4_wkup_clkdm",
         .mpu_irqs       = am33xx_smartreflex1_irqs,
-       .main_clk       = "smartreflex1_fck",
+       .main_clk       = "smartreflex_core_fck",
         .prcm           = {
                 .omap4  = {
                         .clkctrl_offs   = 
AM33XX_CM_WKUP_SMARTREFLEX1_CLKCTRL_OFFSET,


Regards,
Igor.

Re: AM335x: Beaglebone stops to boot with current git kernel

[Jean Pihet]

Hi,

On Wed, Nov 14, 2012 at 4:28 PM, Igor Mazanov <i.mazanov@gmail.com> wrote:
> Hello,
>
> Beaglebone boot process is broken with the current git kernel. I use
> omap2plus_defconfig for tests.
>
> It looks like the boot process stops due to the last changes in the AM33xx
> clock sysbsystem. A following patch resolves this issue:
>
> diff --git a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
> b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
> index ad8d43b..858e180 100644
> --- a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
> +++ b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
> @@ -586,7 +586,7 @@ static struct omap_hwmod am33xx_smartreflex0_hwmod = {
>         .class          = &am33xx_smartreflex_hwmod_class,
>         .clkdm_name     = "l4_wkup_clkdm",
>         .mpu_irqs       = am33xx_smartreflex0_irqs,
> -       .main_clk       = "smartreflex0_fck",
> +       .main_clk       = "smartreflex_mpu_fck",
>         .prcm           = {
>                 .omap4  = {
>                         .clkctrl_offs   =
> AM33XX_CM_WKUP_SMARTREFLEX0_CLKCTRL_OFFSET,
> @@ -606,7 +606,7 @@ static struct omap_hwmod am33xx_smartreflex1_hwmod = {
>         .class          = &am33xx_smartreflex_hwmod_class,
>         .clkdm_name     = "l4_wkup_clkdm",
>         .mpu_irqs       = am33xx_smartreflex1_irqs,
> -       .main_clk       = "smartreflex1_fck",
> +       .main_clk       = "smartreflex_core_fck",
>         .prcm           = {
>                 .omap4  = {
>                         .clkctrl_offs   =
> AM33XX_CM_WKUP_SMARTREFLEX1_CLKCTRL_OFFSET,
>

About the name field in the hwmod entry: the SR code checks on the
value of "smartreflex_mpu_iva" to differentiate the SR IP blocks and
to apply the correct parameters to each of them. Cf. the function
sr_set_regfields in drivers/power/avs/smartreflex.c.

The patch should change the name of the hwmod entry as well, can you
fold this change in the current patch?

Note: I know the name "smartreflex_mpu_iva" is not perfect since it
does not apply to all OMAP3 variants, maybe we could change the SR
code to be more generic.

Nishant, what do you think?

Regards,
Jean

>
> Regards,
> Igor.
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: AM335x: Beaglebone stops to boot with current git kernel

[Nishanth Menon]

On 11/14/2012 10:41 AM, Jean Pihet wrote:
> Hi,
>
> On Wed, Nov 14, 2012 at 4:28 PM, Igor Mazanov <i.mazanov@gmail.com> wrote:
>> Hello,
>>
>> Beaglebone boot process is broken with the current git kernel. I use
>> omap2plus_defconfig for tests.
>>
>> It looks like the boot process stops due to the last changes in the AM33xx
>> clock sysbsystem. A following patch resolves this issue:
>>
>> diff --git a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
>> b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
>> index ad8d43b..858e180 100644
>> --- a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
>> +++ b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
>> @@ -586,7 +586,7 @@ static struct omap_hwmod am33xx_smartreflex0_hwmod = {
>>          .class          = &am33xx_smartreflex_hwmod_class,
>>          .clkdm_name     = "l4_wkup_clkdm",
>>          .mpu_irqs       = am33xx_smartreflex0_irqs,
>> -       .main_clk       = "smartreflex0_fck",
>> +       .main_clk       = "smartreflex_mpu_fck",
>>          .prcm           = {
>>                  .omap4  = {
>>                          .clkctrl_offs   =
>> AM33XX_CM_WKUP_SMARTREFLEX0_CLKCTRL_OFFSET,
>> @@ -606,7 +606,7 @@ static struct omap_hwmod am33xx_smartreflex1_hwmod = {
>>          .class          = &am33xx_smartreflex_hwmod_class,
>>          .clkdm_name     = "l4_wkup_clkdm",
>>          .mpu_irqs       = am33xx_smartreflex1_irqs,
>> -       .main_clk       = "smartreflex1_fck",
>> +       .main_clk       = "smartreflex_core_fck",
>>          .prcm           = {
>>                  .omap4  = {
>>                          .clkctrl_offs   =
>> AM33XX_CM_WKUP_SMARTREFLEX1_CLKCTRL_OFFSET,
>>
>
> About the name field in the hwmod entry: the SR code checks on the
> value of "smartreflex_mpu_iva" to differentiate the SR IP blocks and
> to apply the correct parameters to each of them. Cf. the function
> sr_set_regfields in drivers/power/avs/smartreflex.c.
>
> The patch should change the name of the hwmod entry as well, can you
> fold this change in the current patch?
>
> Note: I know the name "smartreflex_mpu_iva" is not perfect since it
> does not apply to all OMAP3 variants, maybe we could change the SR
> code to be more generic.
>
> Nishant, what do you think?
>
Might be an better idea to remove the entire function sr_set_regfields 
instead provide the err_weight, max_limit, accum_data, avgweights to 
platform_data.
--
Regards,
Nishanth Menon

Re: AM335x: Beaglebone stops to boot with current git kernel

[Tony Lindgren]

* Jean Pihet <jean.pihet@newoldbits.com> [121114 08:43]:
> 
> The patch should change the name of the hwmod entry as well, can you
> fold this change in the current patch?

This was caused by the merge of omap-for-v3.8/pm into omap-for-v3.8/clock.
I noticed a smilar issue for omap3, but missed at least this one.

Jean, can you please check omap-for-v3.8/clock for the smartreflex
clock names in case there are more issues like this remaining?

Regards,

Tony

Re: AM335x: Beaglebone stops to boot with current git kernel

[Jean Pihet]

Hi Tony,

On Wed, Nov 14, 2012 at 6:51 PM, Tony Lindgren <tony@atomide.com> wrote:
> * Jean Pihet <jean.pihet@newoldbits.com> [121114 08:43]:
>>
>> The patch should change the name of the hwmod entry as well, can you
>> fold this change in the current patch?
>
> This was caused by the merge of omap-for-v3.8/pm into omap-for-v3.8/clock.
> I noticed a smilar issue for omap3, but missed at least this one.
>
> Jean, can you please check omap-for-v3.8/clock for the smartreflex
> clock names in case there are more issues like this remaining?
The hwmod clock names are OK for 3xxx, 36xx, 33xx and 44xx. The hwmod
names are OK excepted for 33xx where they respectively should be
"smartreflex_mpu_iva" and ""smartreflex_core".

This issue is caused by 99e7938d "ARM: OMAP3: clock: Add 3xxx data
using common struct clk" in omap-for-v3.8/clock.

> Regards,
>
> Tony

Regards,
Jean

Re: AM335x: Beaglebone stops to boot with current git kernel

[Tony Lindgren]

* Jean Pihet <jean.pihet@newoldbits.com> [121115 06:49]:
> Hi Tony,
> 
> On Wed, Nov 14, 2012 at 6:51 PM, Tony Lindgren <tony@atomide.com> wrote:
> > * Jean Pihet <jean.pihet@newoldbits.com> [121114 08:43]:
> >>
> >> The patch should change the name of the hwmod entry as well, can you
> >> fold this change in the current patch?
> >
> > This was caused by the merge of omap-for-v3.8/pm into omap-for-v3.8/clock.
> > I noticed a smilar issue for omap3, but missed at least this one.
> >
> > Jean, can you please check omap-for-v3.8/clock for the smartreflex
> > clock names in case there are more issues like this remaining?
> The hwmod clock names are OK for 3xxx, 36xx, 33xx and 44xx. The hwmod
> names are OK excepted for 33xx where they respectively should be
> "smartreflex_mpu_iva" and ""smartreflex_core".
> 
> This issue is caused by 99e7938d "ARM: OMAP3: clock: Add 3xxx data
> using common struct clk" in omap-for-v3.8/clock.

OK thanks for checking.

Regards,

Tony

Re: AM335x: Beaglebone stops to boot with current git kernel

[Tony Lindgren]

* Jean Pihet <jean.pihet@newoldbits.com> [121114 08:43]:
> On Wed, Nov 14, 2012 at 4:28 PM, Igor Mazanov <i.mazanov@gmail.com> wrote:
> >
> > Beaglebone boot process is broken with the current git kernel. I use
> > omap2plus_defconfig for tests.
> >
> > It looks like the boot process stops due to the last changes in the AM33xx
> > clock sysbsystem. A following patch resolves this issue:
...
 
> The patch should change the name of the hwmod entry as well, can you
> fold this change in the current patch?

Any news on updating this?

Regards,

Tony

Re: AM335x: Beaglebone stops to boot with current git kernel

[Igor Mazanov]

On Wed, Nov 21, 2012 at 9:38 PM, Tony Lindgren <tony@atomide.com> wrote:
> * Jean Pihet <jean.pihet@newoldbits.com> [121114 08:43]:
>> On Wed, Nov 14, 2012 at 4:28 PM, Igor Mazanov <i.mazanov@gmail.com> wrote:
>> >
>> > Beaglebone boot process is broken with the current git kernel. I use
>> > omap2plus_defconfig for tests.
>> >
>> > It looks like the boot process stops due to the last changes in the AM33xx
>> > clock sysbsystem. A following patch resolves this issue:
> ...
>
>> The patch should change the name of the hwmod entry as well, can you
>> fold this change in the current patch?
>
> Any news on updating this?

The current kernel boots, but after a switching to CCF doesn't work
the debugss - it's just disabled in the current hwmod code. So, it
looks like we can't  use JTAG to connect to the running kernel.

Regards,
Igor.

> Regards,
>
> Tony

Re: AM335x: Beaglebone stops to boot with current git kernel

[Vaibhav Hiremath]

On 11/22/2012 1:30 AM, Igor Mazanov wrote:
> On Wed, Nov 21, 2012 at 9:38 PM, Tony Lindgren <tony@atomide.com> wrote:
>> * Jean Pihet <jean.pihet@newoldbits.com> [121114 08:43]:
>>> On Wed, Nov 14, 2012 at 4:28 PM, Igor Mazanov <i.mazanov@gmail.com> wrote:
>>>>
>>>> Beaglebone boot process is broken with the current git kernel. I use
>>>> omap2plus_defconfig for tests.
>>>>
>>>> It looks like the boot process stops due to the last changes in the AM33xx
>>>> clock sysbsystem. A following patch resolves this issue:
>> ...
>>
>>> The patch should change the name of the hwmod entry as well, can you
>>> fold this change in the current patch?
>>
>> Any news on updating this?
> 
> The current kernel boots, but after a switching to CCF doesn't work
> the debugss - it's just disabled in the current hwmod code. So, it
> looks like we can't  use JTAG to connect to the running kernel.
> 

just resumed from vacation...

JTAG clock will get disabled because, CONFIG_OMAP_RESET_CLOCKS will
disable unused clocks, so as debugss clock.

There is another thread started by Joel on the similar issue,

http://www.mail-archive.com/linux-omap@vger.kernel.org/msg80863.html

Something below should be done for debugss on AM33xx,

diff --git a/arch/arm/mach-omap2/clock33xx_data.c
b/arch/arm/mach-omap2/clock33xx_data.c
index 17e3de5..60e0b53 100644
--- a/arch/arm/mach-omap2/clock33xx_data.c
+++ b/arch/arm/mach-omap2/clock33xx_data.c
@@ -584,6 +584,9 @@ static struct clk debugss_ick = {
        .clkdm_name     = "l3_aon_clkdm",
        .parent         = &dpll_core_m4_ck,
        .ops            = &clkops_omap2_dflt,
+#ifdef CONFIG_DEBUG_KERNEL
+       .flags          = ENABLE_ON_INIT,
+#endif
        .enable_reg     = AM33XX_CM_WKUP_DEBUGSS_CLKCTRL,
        .enable_bit     = AM33XX_MODULEMODE_SWCTRL,
        .recalc         = &followparent_recalc,



Thanks,
Vaibhav

> Regards,
> Igor.
> 
>> Regards,
>>
>> Tony
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

Re: AM335x: Beaglebone stops to boot with current git kernel

[Igor Mazanov]

On Thu, Nov 22, 2012 at 9:42 AM, Vaibhav Hiremath <hvaibhav@ti.com> wrote:
>
>
> On 11/22/2012 1:30 AM, Igor Mazanov wrote:
>> On Wed, Nov 21, 2012 at 9:38 PM, Tony Lindgren <tony@atomide.com> wrote:
>>> * Jean Pihet <jean.pihet@newoldbits.com> [121114 08:43]:
>>>> On Wed, Nov 14, 2012 at 4:28 PM, Igor Mazanov <i.mazanov@gmail.com> wrote:
>>>>>
>>>>> Beaglebone boot process is broken with the current git kernel. I use
>>>>> omap2plus_defconfig for tests.
>>>>>
>>>>> It looks like the boot process stops due to the last changes in the AM33xx
>>>>> clock sysbsystem. A following patch resolves this issue:
>>> ...
>>>
>>>> The patch should change the name of the hwmod entry as well, can you
>>>> fold this change in the current patch?
>>>
>>> Any news on updating this?
>>
>> The current kernel boots, but after a switching to CCF doesn't work
>> the debugss - it's just disabled in the current hwmod code. So, it
>> looks like we can't  use JTAG to connect to the running kernel.
>>
>
> just resumed from vacation...
>
> JTAG clock will get disabled because, CONFIG_OMAP_RESET_CLOCKS will
> disable unused clocks, so as debugss clock.
>
> There is another thread started by Joel on the similar issue,
>
> http://www.mail-archive.com/linux-omap@vger.kernel.org/msg80863.html
>
> Something below should be done for debugss on AM33xx,
>
> diff --git a/arch/arm/mach-omap2/clock33xx_data.c
> b/arch/arm/mach-omap2/clock33xx_data.c
> index 17e3de5..60e0b53 100644
> --- a/arch/arm/mach-omap2/clock33xx_data.c
> +++ b/arch/arm/mach-omap2/clock33xx_data.c
> @@ -584,6 +584,9 @@ static struct clk debugss_ick = {
>         .clkdm_name     = "l3_aon_clkdm",
>         .parent         = &dpll_core_m4_ck,
>         .ops            = &clkops_omap2_dflt,
> +#ifdef CONFIG_DEBUG_KERNEL
> +       .flags          = ENABLE_ON_INIT,
> +#endif
>         .enable_reg     = AM33XX_CM_WKUP_DEBUGSS_CLKCTRL,
>         .enable_bit     = AM33XX_MODULEMODE_SWCTRL,
>         .recalc         = &followparent_recalc,

Yes, I noticed this thread. But now a clock subsystem in the current
kernel is switched to Common Clock Framework and debugss (and several
another modules) is disabled (#if 0 .... #endif) in
omap_hwmod_33xx_data.c.

>From omap_hwmod_33xx_data.c:

/*
 * Modules omap_hwmod structures
 *
 * The following IPs are excluded for the moment because:
 * - They do not need an explicit SW control using omap_hwmod API.
 * - They still need to be validated with the driver
 *   properly adapted to omap_hwmod / omap_device
 *
 *    - cEFUSE (doesn't fall under any ocp_if)
 *    - clkdiv32k
 *    - debugss
 *    - ocmc ram
 *    - ocp watch point
 *    - aes0
 *    - sha0
 */

I uncommented the debugss entry in the omap_hwmod settings, but only
got a warning like:

 CC      arch/arm/mach-omap2/omap_hwmod_33xx_data.o
arch/arm/mach-omap2/omap_hwmod_33xx_data.c:472:26: warning:
'am33xx_debugss_hwmod' defined but not used [-Wunused-variable]

By the way, I need to use JTAG to trace a problem described in this thread:

http://marc.info/?l=linux-omap&m=135307646415429&w=2

May be, it's the clocks related issue too...

> Thanks,
> Vaibhav
>
>> Regards,
>> Igor.
>>
>>> Regards,
>>>
>>> Tony
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>

RE: AM335x: Beaglebone stops to boot with current git kernel

[Hiremath, Vaibhav]

On Thu, Nov 22, 2012 at 17:46:50, Igor Mazanov wrote:
> On Thu, Nov 22, 2012 at 9:42 AM, Vaibhav Hiremath <hvaibhav@ti.com> wrote:
> >
> >
> > On 11/22/2012 1:30 AM, Igor Mazanov wrote:
> >> On Wed, Nov 21, 2012 at 9:38 PM, Tony Lindgren <tony@atomide.com> wrote:
> >>> * Jean Pihet <jean.pihet@newoldbits.com> [121114 08:43]:
> >>>> On Wed, Nov 14, 2012 at 4:28 PM, Igor Mazanov <i.mazanov@gmail.com> wrote:
> >>>>>
> >>>>> Beaglebone boot process is broken with the current git kernel. I use
> >>>>> omap2plus_defconfig for tests.
> >>>>>
> >>>>> It looks like the boot process stops due to the last changes in the AM33xx
> >>>>> clock sysbsystem. A following patch resolves this issue:
> >>> ...
> >>>
> >>>> The patch should change the name of the hwmod entry as well, can you
> >>>> fold this change in the current patch?
> >>>
> >>> Any news on updating this?
> >>
> >> The current kernel boots, but after a switching to CCF doesn't work
> >> the debugss - it's just disabled in the current hwmod code. So, it
> >> looks like we can't  use JTAG to connect to the running kernel.
> >>
> >
> > just resumed from vacation...
> >
> > JTAG clock will get disabled because, CONFIG_OMAP_RESET_CLOCKS will
> > disable unused clocks, so as debugss clock.
> >
> > There is another thread started by Joel on the similar issue,
> >
> > http://www.mail-archive.com/linux-omap@vger.kernel.org/msg80863.html
> >
> > Something below should be done for debugss on AM33xx,
> >
> > diff --git a/arch/arm/mach-omap2/clock33xx_data.c
> > b/arch/arm/mach-omap2/clock33xx_data.c
> > index 17e3de5..60e0b53 100644
> > --- a/arch/arm/mach-omap2/clock33xx_data.c
> > +++ b/arch/arm/mach-omap2/clock33xx_data.c
> > @@ -584,6 +584,9 @@ static struct clk debugss_ick = {
> >         .clkdm_name     = "l3_aon_clkdm",
> >         .parent         = &dpll_core_m4_ck,
> >         .ops            = &clkops_omap2_dflt,
> > +#ifdef CONFIG_DEBUG_KERNEL
> > +       .flags          = ENABLE_ON_INIT,
> > +#endif
> >         .enable_reg     = AM33XX_CM_WKUP_DEBUGSS_CLKCTRL,
> >         .enable_bit     = AM33XX_MODULEMODE_SWCTRL,
> >         .recalc         = &followparent_recalc,
> 
> Yes, I noticed this thread. But now a clock subsystem in the current
> kernel is switched to Common Clock Framework and debugss (and several
> another modules) is disabled

Still this can be handled and enabled during init.


> (#if 0 .... #endif) in
> omap_hwmod_33xx_data.c.
> 
> From omap_hwmod_33xx_data.c:
> 
> /*
>  * Modules omap_hwmod structures
>  *
>  * The following IPs are excluded for the moment because:
>  * - They do not need an explicit SW control using omap_hwmod API.
>  * - They still need to be validated with the driver
>  *   properly adapted to omap_hwmod / omap_device
>  *
>  *    - cEFUSE (doesn't fall under any ocp_if)
>  *    - clkdiv32k
>  *    - debugss
>  *    - ocmc ram
>  *    - ocp watch point
>  *    - aes0
>  *    - sha0
>  */
> 
> I uncommented the debugss entry in the omap_hwmod settings, but only
> got a warning like:
> 
>  CC      arch/arm/mach-omap2/omap_hwmod_33xx_data.o
> arch/arm/mach-omap2/omap_hwmod_33xx_data.c:472:26: warning:
> 'am33xx_debugss_hwmod' defined but not used [-Wunused-variable]
> 
> By the way, I need to use JTAG to trace a problem described in this thread:
> 
> http://marc.info/?l=linux-omap&m=135307646415429&w=2
> 
> May be, it's the clocks related issue too...
> 


I have quickly created patch for you, can you try below patch and let me 
know?



diff --git a/arch/arm/mach-omap2/cclock33xx_data.c b/arch/arm/mach-omap2/cclock33xx_data.c
index ea64ad6..c9af78c 100644
--- a/arch/arm/mach-omap2/cclock33xx_data.c
+++ b/arch/arm/mach-omap2/cclock33xx_data.c
@@ -920,6 +920,7 @@ static const char *enable_init_clks[] = {
        "l4hs_gclk",
        "l4fw_gclk",
        "l4ls_gclk",
+       "debugss_ick",
 };

 int __init am33xx_clk_init(void)
diff --git a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
index ad8d43b..750b897 100644
--- a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
+++ b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
@@ -460,27 +460,6 @@ static struct omap_hwmod am33xx_clkdiv32k_hwmod = {
        },
 };

-/*
- * 'debugss' class
- * debug sub system
- */
-static struct omap_hwmod_class am33xx_debugss_hwmod_class = {
-       .name           = "debugss",
-};
-
-static struct omap_hwmod am33xx_debugss_hwmod = {
-       .name           = "debugss",
-       .class          = &am33xx_debugss_hwmod_class,
-       .clkdm_name     = "l3_aon_clkdm",
-       .main_clk       = "debugss_ick",
-       .prcm           = {
-               .omap4  = {
-                       .clkctrl_offs   = AM33XX_CM_WKUP_DEBUGSS_CLKCTRL_OFFSET,
-                       .modulemode     = MODULEMODE_SWCTRL,
-               },
-       },
-};
-
/* ocmcram */
 static struct omap_hwmod_class am33xx_ocmcram_hwmod_class = {
        .name = "ocmcram",
@@ -570,6 +549,28 @@ static struct omap_hwmod am33xx_sha0_hwmod = {

 #endif

+/*
+ * 'debugss' class
+ * debug sub system
+ */
+static struct omap_hwmod_class am33xx_debugss_hwmod_class = {
+       .name           = "debugss",
+};
+
+static struct omap_hwmod am33xx_debugss_hwmod = {
+       .name           = "debugss",
+       .class          = &am33xx_debugss_hwmod_class,
+       .clkdm_name     = "l3_aon_clkdm",
+       .main_clk       = "debugss_ick",
+       .flags          =  (HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET),
+       .prcm           = {
+               .omap4  = {
+                       .clkctrl_offs   = AM33XX_CM_WKUP_DEBUGSS_CLKCTRL_OFFSET,
+                       .modulemode     = MODULEMODE_SWCTRL,
+               },
+       },
+};
+
 /* 'smartreflex' class */
 static struct omap_hwmod_class am33xx_smartreflex_hwmod_class = {
        .name           = "smartreflex",
@@ -2261,6 +2262,24 @@ static struct omap_hwmod_ocp_if am33xx_l3_main__gfx = {
        .user           = OCP_USER_MPU | OCP_USER_SDMA,
 };

+/* l3_main -> debugss */
+static struct omap_hwmod_addr_space am33xx_debugss_addrs[] = {
+       {
+               .pa_start       = 0x4b000000,
+               .pa_end         = 0x4b000000 + SZ_16M - 1,
+               .flags          = ADDR_TYPE_RT
+       },
+       { }
+};
+
+static struct omap_hwmod_ocp_if am33xx_l3_main__debugss = {
+       .master         = &am33xx_l3_main_hwmod,
+       .slave          = &am33xx_debugss_hwmod,
+       .clk            = "debugss_ick",
+       .addr           = am33xx_debugss_addrs,
+       .user           = OCP_USER_MPU,
+};
+
 /* l4 wkup -> smartreflex0 */
 static struct omap_hwmod_addr_space am33xx_smartreflex0_addrs[] = {
        {
@@ -3315,6 +3334,7 @@ static struct omap_hwmod_ocp_if *am33xx_hwmod_ocp_ifs[] __initdata = {
        &am33xx_pruss__l3_main,
        &am33xx_wkup_m3__l4_wkup,
        &am33xx_gfx__l3_main,
+       &am33xx_l3_main__debugss,
        &am33xx_l4_wkup__wkup_m3,
        &am33xx_l4_wkup__control,
        &am33xx_l4_wkup__smartreflex0,


Thanks,
Vaibhav

RE: AM335x: Beaglebone stops to boot with current git kernel

[Hiremath, Vaibhav]

On Thu, Nov 22, 2012 at 20:17:26, Hiremath, Vaibhav wrote:
> On Thu, Nov 22, 2012 at 17:46:50, Igor Mazanov wrote:
> > On Thu, Nov 22, 2012 at 9:42 AM, Vaibhav Hiremath <hvaibhav@ti.com> wrote:
> > >
> > >
> > > On 11/22/2012 1:30 AM, Igor Mazanov wrote:
> > >> On Wed, Nov 21, 2012 at 9:38 PM, Tony Lindgren <tony@atomide.com> wrote:
> > >>> * Jean Pihet <jean.pihet@newoldbits.com> [121114 08:43]:
> > >>>> On Wed, Nov 14, 2012 at 4:28 PM, Igor Mazanov <i.mazanov@gmail.com> wrote:
> > >>>>>
> > >>>>> Beaglebone boot process is broken with the current git kernel. I use
> > >>>>> omap2plus_defconfig for tests.
> > >>>>>
> > >>>>> It looks like the boot process stops due to the last changes in the AM33xx
> > >>>>> clock sysbsystem. A following patch resolves this issue:
> > >>> ...
> > >>>
> > >>>> The patch should change the name of the hwmod entry as well, can you
> > >>>> fold this change in the current patch?
> > >>>
> > >>> Any news on updating this?
> > >>
> > >> The current kernel boots, but after a switching to CCF doesn't work
> > >> the debugss - it's just disabled in the current hwmod code. So, it
> > >> looks like we can't  use JTAG to connect to the running kernel.
> > >>
> > >
> > > just resumed from vacation...
> > >
> > > JTAG clock will get disabled because, CONFIG_OMAP_RESET_CLOCKS will
> > > disable unused clocks, so as debugss clock.
> > >
> > > There is another thread started by Joel on the similar issue,
> > >
> > > http://www.mail-archive.com/linux-omap@vger.kernel.org/msg80863.html
> > >
> > > Something below should be done for debugss on AM33xx,
> > >
> > > diff --git a/arch/arm/mach-omap2/clock33xx_data.c
> > > b/arch/arm/mach-omap2/clock33xx_data.c
> > > index 17e3de5..60e0b53 100644
> > > --- a/arch/arm/mach-omap2/clock33xx_data.c
> > > +++ b/arch/arm/mach-omap2/clock33xx_data.c
> > > @@ -584,6 +584,9 @@ static struct clk debugss_ick = {
> > >         .clkdm_name     = "l3_aon_clkdm",
> > >         .parent         = &dpll_core_m4_ck,
> > >         .ops            = &clkops_omap2_dflt,
> > > +#ifdef CONFIG_DEBUG_KERNEL
> > > +       .flags          = ENABLE_ON_INIT,
> > > +#endif
> > >         .enable_reg     = AM33XX_CM_WKUP_DEBUGSS_CLKCTRL,
> > >         .enable_bit     = AM33XX_MODULEMODE_SWCTRL,
> > >         .recalc         = &followparent_recalc,
> > 
> > Yes, I noticed this thread. But now a clock subsystem in the current
> > kernel is switched to Common Clock Framework and debugss (and several
> > another modules) is disabled
> 
> Still this can be handled and enabled during init.
> 
> 
> > (#if 0 .... #endif) in
> > omap_hwmod_33xx_data.c.
> > 
> > From omap_hwmod_33xx_data.c:
> > 
> > /*
> >  * Modules omap_hwmod structures
> >  *
> >  * The following IPs are excluded for the moment because:
> >  * - They do not need an explicit SW control using omap_hwmod API.
> >  * - They still need to be validated with the driver
> >  *   properly adapted to omap_hwmod / omap_device
> >  *
> >  *    - cEFUSE (doesn't fall under any ocp_if)
> >  *    - clkdiv32k
> >  *    - debugss
> >  *    - ocmc ram
> >  *    - ocp watch point
> >  *    - aes0
> >  *    - sha0
> >  */
> > 
> > I uncommented the debugss entry in the omap_hwmod settings, but only
> > got a warning like:
> > 
> >  CC      arch/arm/mach-omap2/omap_hwmod_33xx_data.o
> > arch/arm/mach-omap2/omap_hwmod_33xx_data.c:472:26: warning:
> > 'am33xx_debugss_hwmod' defined but not used [-Wunused-variable]
> > 
> > By the way, I need to use JTAG to trace a problem described in this thread:
> > 
> > http://marc.info/?l=linux-omap&m=135307646415429&w=2
> > 
> > May be, it's the clocks related issue too...
> > 
> 
> 
> I have quickly created patch for you, can you try below patch and let me 
> know?
> 
> 
> 
> diff --git a/arch/arm/mach-omap2/cclock33xx_data.c b/arch/arm/mach-omap2/cclock33xx_data.c
> index ea64ad6..c9af78c 100644
> --- a/arch/arm/mach-omap2/cclock33xx_data.c
> +++ b/arch/arm/mach-omap2/cclock33xx_data.c
> @@ -920,6 +920,7 @@ static const char *enable_init_clks[] = {
>         "l4hs_gclk",
>         "l4fw_gclk",
>         "l4ls_gclk",
> +       "debugss_ick",
>  };
> 
>  int __init am33xx_clk_init(void)
> diff --git a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
> index ad8d43b..750b897 100644
> --- a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
> +++ b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
> @@ -460,27 +460,6 @@ static struct omap_hwmod am33xx_clkdiv32k_hwmod = {
>         },
>  };
> 
> -/*
> - * 'debugss' class
> - * debug sub system
> - */
> -static struct omap_hwmod_class am33xx_debugss_hwmod_class = {
> -       .name           = "debugss",
> -};
> -
> -static struct omap_hwmod am33xx_debugss_hwmod = {
> -       .name           = "debugss",
> -       .class          = &am33xx_debugss_hwmod_class,
> -       .clkdm_name     = "l3_aon_clkdm",
> -       .main_clk       = "debugss_ick",
> -       .prcm           = {
> -               .omap4  = {
> -                       .clkctrl_offs   = AM33XX_CM_WKUP_DEBUGSS_CLKCTRL_OFFSET,
> -                       .modulemode     = MODULEMODE_SWCTRL,
> -               },
> -       },
> -};
> -
> /* ocmcram */
>  static struct omap_hwmod_class am33xx_ocmcram_hwmod_class = {
>         .name = "ocmcram",
> @@ -570,6 +549,28 @@ static struct omap_hwmod am33xx_sha0_hwmod = {
> 
>  #endif
> 
> +/*
> + * 'debugss' class
> + * debug sub system
> + */
> +static struct omap_hwmod_class am33xx_debugss_hwmod_class = {
> +       .name           = "debugss",
> +};
> +
> +static struct omap_hwmod am33xx_debugss_hwmod = {
> +       .name           = "debugss",
> +       .class          = &am33xx_debugss_hwmod_class,
> +       .clkdm_name     = "l3_aon_clkdm",
> +       .main_clk       = "debugss_ick",
> +       .flags          =  (HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET),
> +       .prcm           = {
> +               .omap4  = {
> +                       .clkctrl_offs   = AM33XX_CM_WKUP_DEBUGSS_CLKCTRL_OFFSET,
> +                       .modulemode     = MODULEMODE_SWCTRL,
> +               },
> +       },
> +};
> +
>  /* 'smartreflex' class */
>  static struct omap_hwmod_class am33xx_smartreflex_hwmod_class = {
>         .name           = "smartreflex",
> @@ -2261,6 +2262,24 @@ static struct omap_hwmod_ocp_if am33xx_l3_main__gfx = {
>         .user           = OCP_USER_MPU | OCP_USER_SDMA,
>  };
> 
> +/* l3_main -> debugss */
> +static struct omap_hwmod_addr_space am33xx_debugss_addrs[] = {
> +       {
> +               .pa_start       = 0x4b000000,
> +               .pa_end         = 0x4b000000 + SZ_16M - 1,
> +               .flags          = ADDR_TYPE_RT
> +       },
> +       { }
> +};
> +
> +static struct omap_hwmod_ocp_if am33xx_l3_main__debugss = {
> +       .master         = &am33xx_l3_main_hwmod,
> +       .slave          = &am33xx_debugss_hwmod,
> +       .clk            = "debugss_ick",
> +       .addr           = am33xx_debugss_addrs,
> +       .user           = OCP_USER_MPU,
> +};
> +
>  /* l4 wkup -> smartreflex0 */
>  static struct omap_hwmod_addr_space am33xx_smartreflex0_addrs[] = {
>         {
> @@ -3315,6 +3334,7 @@ static struct omap_hwmod_ocp_if *am33xx_hwmod_ocp_ifs[] __initdata = {
>         &am33xx_pruss__l3_main,
>         &am33xx_wkup_m3__l4_wkup,
>         &am33xx_gfx__l3_main,
> +       &am33xx_l3_main__debugss,
>         &am33xx_l4_wkup__wkup_m3,
>         &am33xx_l4_wkup__control,
>         &am33xx_l4_wkup__smartreflex0,
> 
> 



Missed to mention that,

I have boot tested it on Bone platform and made sure that debugs module 
stays enabled after boot (after applying this patch).


Thanks,
Vaibhav

Re: AM335x: Beaglebone stops to boot with current git kernel

[Igor Mazanov]

On Thu, Nov 22, 2012 at 6:49 PM, Hiremath, Vaibhav <hvaibhav@ti.com> wrote:
> On Thu, Nov 22, 2012 at 20:17:26, Hiremath, Vaibhav wrote:
>> On Thu, Nov 22, 2012 at 17:46:50, Igor Mazanov wrote:
>> > On Thu, Nov 22, 2012 at 9:42 AM, Vaibhav Hiremath <hvaibhav@ti.com> wrote:
>> > >
>> > >
>> > > On 11/22/2012 1:30 AM, Igor Mazanov wrote:
>> > >> On Wed, Nov 21, 2012 at 9:38 PM, Tony Lindgren <tony@atomide.com> wrote:
>> > >>> * Jean Pihet <jean.pihet@newoldbits.com> [121114 08:43]:
>> > >>>> On Wed, Nov 14, 2012 at 4:28 PM, Igor Mazanov <i.mazanov@gmail.com> wrote:
>> > >>>>>
>> > >>>>> Beaglebone boot process is broken with the current git kernel. I use
>> > >>>>> omap2plus_defconfig for tests.
>> > >>>>>
>> > >>>>> It looks like the boot process stops due to the last changes in the AM33xx
>> > >>>>> clock sysbsystem. A following patch resolves this issue:
>> > >>> ...
>> > >>>
>> > >>>> The patch should change the name of the hwmod entry as well, can you
>> > >>>> fold this change in the current patch?
>> > >>>
>> > >>> Any news on updating this?
>> > >>
>> > >> The current kernel boots, but after a switching to CCF doesn't work
>> > >> the debugss - it's just disabled in the current hwmod code. So, it
>> > >> looks like we can't  use JTAG to connect to the running kernel.
>> > >>
>> > >
>> > > just resumed from vacation...
>> > >
>> > > JTAG clock will get disabled because, CONFIG_OMAP_RESET_CLOCKS will
>> > > disable unused clocks, so as debugss clock.
>> > >
>> > > There is another thread started by Joel on the similar issue,
>> > >
>> > > http://www.mail-archive.com/linux-omap@vger.kernel.org/msg80863.html
>> > >
>> > > Something below should be done for debugss on AM33xx,
>> > >
>> > > diff --git a/arch/arm/mach-omap2/clock33xx_data.c
>> > > b/arch/arm/mach-omap2/clock33xx_data.c
>> > > index 17e3de5..60e0b53 100644
>> > > --- a/arch/arm/mach-omap2/clock33xx_data.c
>> > > +++ b/arch/arm/mach-omap2/clock33xx_data.c
>> > > @@ -584,6 +584,9 @@ static struct clk debugss_ick = {
>> > >         .clkdm_name     = "l3_aon_clkdm",
>> > >         .parent         = &dpll_core_m4_ck,
>> > >         .ops            = &clkops_omap2_dflt,
>> > > +#ifdef CONFIG_DEBUG_KERNEL
>> > > +       .flags          = ENABLE_ON_INIT,
>> > > +#endif
>> > >         .enable_reg     = AM33XX_CM_WKUP_DEBUGSS_CLKCTRL,
>> > >         .enable_bit     = AM33XX_MODULEMODE_SWCTRL,
>> > >         .recalc         = &followparent_recalc,
>> >
>> > Yes, I noticed this thread. But now a clock subsystem in the current
>> > kernel is switched to Common Clock Framework and debugss (and several
>> > another modules) is disabled
>>
>> Still this can be handled and enabled during init.
>>
>>
>> > (#if 0 .... #endif) in
>> > omap_hwmod_33xx_data.c.
>> >
>> > From omap_hwmod_33xx_data.c:
>> >
>> > /*
>> >  * Modules omap_hwmod structures
>> >  *
>> >  * The following IPs are excluded for the moment because:
>> >  * - They do not need an explicit SW control using omap_hwmod API.
>> >  * - They still need to be validated with the driver
>> >  *   properly adapted to omap_hwmod / omap_device
>> >  *
>> >  *    - cEFUSE (doesn't fall under any ocp_if)
>> >  *    - clkdiv32k
>> >  *    - debugss
>> >  *    - ocmc ram
>> >  *    - ocp watch point
>> >  *    - aes0
>> >  *    - sha0
>> >  */
>> >
>> > I uncommented the debugss entry in the omap_hwmod settings, but only
>> > got a warning like:
>> >
>> >  CC      arch/arm/mach-omap2/omap_hwmod_33xx_data.o
>> > arch/arm/mach-omap2/omap_hwmod_33xx_data.c:472:26: warning:
>> > 'am33xx_debugss_hwmod' defined but not used [-Wunused-variable]
>> >
>> > By the way, I need to use JTAG to trace a problem described in this thread:
>> >
>> > http://marc.info/?l=linux-omap&m=135307646415429&w=2
>> >
>> > May be, it's the clocks related issue too...
>> >
>>
>>
>> I have quickly created patch for you, can you try below patch and let me
>> know?
>>
>>
>>
>> diff --git a/arch/arm/mach-omap2/cclock33xx_data.c b/arch/arm/mach-omap2/cclock33xx_data.c
>> index ea64ad6..c9af78c 100644
>> --- a/arch/arm/mach-omap2/cclock33xx_data.c
>> +++ b/arch/arm/mach-omap2/cclock33xx_data.c
>> @@ -920,6 +920,7 @@ static const char *enable_init_clks[] = {
>>         "l4hs_gclk",
>>         "l4fw_gclk",
>>         "l4ls_gclk",
>> +       "debugss_ick",
>>  };
>>
>>  int __init am33xx_clk_init(void)
>> diff --git a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
>> index ad8d43b..750b897 100644
>> --- a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
>> +++ b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
>> @@ -460,27 +460,6 @@ static struct omap_hwmod am33xx_clkdiv32k_hwmod = {
>>         },
>>  };
>>
>> -/*
>> - * 'debugss' class
>> - * debug sub system
>> - */
>> -static struct omap_hwmod_class am33xx_debugss_hwmod_class = {
>> -       .name           = "debugss",
>> -};
>> -
>> -static struct omap_hwmod am33xx_debugss_hwmod = {
>> -       .name           = "debugss",
>> -       .class          = &am33xx_debugss_hwmod_class,
>> -       .clkdm_name     = "l3_aon_clkdm",
>> -       .main_clk       = "debugss_ick",
>> -       .prcm           = {
>> -               .omap4  = {
>> -                       .clkctrl_offs   = AM33XX_CM_WKUP_DEBUGSS_CLKCTRL_OFFSET,
>> -                       .modulemode     = MODULEMODE_SWCTRL,
>> -               },
>> -       },
>> -};
>> -
>> /* ocmcram */
>>  static struct omap_hwmod_class am33xx_ocmcram_hwmod_class = {
>>         .name = "ocmcram",
>> @@ -570,6 +549,28 @@ static struct omap_hwmod am33xx_sha0_hwmod = {
>>
>>  #endif
>>
>> +/*
>> + * 'debugss' class
>> + * debug sub system
>> + */
>> +static struct omap_hwmod_class am33xx_debugss_hwmod_class = {
>> +       .name           = "debugss",
>> +};
>> +
>> +static struct omap_hwmod am33xx_debugss_hwmod = {
>> +       .name           = "debugss",
>> +       .class          = &am33xx_debugss_hwmod_class,
>> +       .clkdm_name     = "l3_aon_clkdm",
>> +       .main_clk       = "debugss_ick",
>> +       .flags          =  (HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET),
>> +       .prcm           = {
>> +               .omap4  = {
>> +                       .clkctrl_offs   = AM33XX_CM_WKUP_DEBUGSS_CLKCTRL_OFFSET,
>> +                       .modulemode     = MODULEMODE_SWCTRL,
>> +               },
>> +       },
>> +};
>> +
>>  /* 'smartreflex' class */
>>  static struct omap_hwmod_class am33xx_smartreflex_hwmod_class = {
>>         .name           = "smartreflex",
>> @@ -2261,6 +2262,24 @@ static struct omap_hwmod_ocp_if am33xx_l3_main__gfx = {
>>         .user           = OCP_USER_MPU | OCP_USER_SDMA,
>>  };
>>
>> +/* l3_main -> debugss */
>> +static struct omap_hwmod_addr_space am33xx_debugss_addrs[] = {
>> +       {
>> +               .pa_start       = 0x4b000000,
>> +               .pa_end         = 0x4b000000 + SZ_16M - 1,
>> +               .flags          = ADDR_TYPE_RT
>> +       },
>> +       { }
>> +};
>> +
>> +static struct omap_hwmod_ocp_if am33xx_l3_main__debugss = {
>> +       .master         = &am33xx_l3_main_hwmod,
>> +       .slave          = &am33xx_debugss_hwmod,
>> +       .clk            = "debugss_ick",
>> +       .addr           = am33xx_debugss_addrs,
>> +       .user           = OCP_USER_MPU,
>> +};
>> +
>>  /* l4 wkup -> smartreflex0 */
>>  static struct omap_hwmod_addr_space am33xx_smartreflex0_addrs[] = {
>>         {
>> @@ -3315,6 +3334,7 @@ static struct omap_hwmod_ocp_if *am33xx_hwmod_ocp_ifs[] __initdata = {
>>         &am33xx_pruss__l3_main,
>>         &am33xx_wkup_m3__l4_wkup,
>>         &am33xx_gfx__l3_main,
>> +       &am33xx_l3_main__debugss,
>>         &am33xx_l4_wkup__wkup_m3,
>>         &am33xx_l4_wkup__control,
>>         &am33xx_l4_wkup__smartreflex0,
>>
>>
>
>
>
> Missed to mention that,
>
> I have boot tested it on Bone platform and made sure that debugs module
> stays enabled after boot (after applying this patch).
>

I applied your patch and it works for me too. JTAG interface is
working now. Thanks!

Regards,
Igor.

> Thanks,
> Vaibhav

Re: AM335x: Beaglebone stops to boot with current git kernel

[Joel A Fernandes]

Hi Vaibhav, Igor,

On and off due to vacation time too,..

Not sure but I missed the below patch from Vaibhav as it probably
wasn't copied to linux-omap so I got confused which patch was Igor
testing, whether it was the one in which we set ENABLE_ON_INIT or the
one in which hwmod data is changed.

I think Igor tried the latter and it works. In that case, I guess we
can drop the ENABLE_ON_INIT patch if this is a better fix. I had some
comments though...

On Thu, Nov 22, 2012 at 10:40 AM, Igor Mazanov <i.mazanov@gmail.com> wrote:
> On Thu, Nov 22, 2012 at 6:49 PM, Hiremath, Vaibhav <hvaibhav@ti.com> wrote:
[..]
>>> I have quickly created patch for you, can you try below patch and let me
>>> know?
>>>
>>>
>>>
>>> diff --git a/arch/arm/mach-omap2/cclock33xx_data.c b/arch/arm/mach-omap2/cclock33xx_data.c
>>> index ea64ad6..c9af78c 100644
>>> --- a/arch/arm/mach-omap2/cclock33xx_data.c
>>> +++ b/arch/arm/mach-omap2/cclock33xx_data.c
>>> @@ -920,6 +920,7 @@ static const char *enable_init_clks[] = {
>>>         "l4hs_gclk",
>>>         "l4fw_gclk",
>>>         "l4ls_gclk",
>>> +       "debugss_ick",
>>>  };
>>>
>>>  int __init am33xx_clk_init(void)
>>> diff --git a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
>>> index ad8d43b..750b897 100644
>>> --- a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
>>> +++ b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
>>> @@ -460,27 +460,6 @@ static struct omap_hwmod am33xx_clkdiv32k_hwmod = {
>>>         },
>>>  };
>>>
>>> -/*
>>> - * 'debugss' class
>>> - * debug sub system
>>> - */
>>> -static struct omap_hwmod_class am33xx_debugss_hwmod_class = {
>>> -       .name           = "debugss",
>>> -};
>>> -
>>> -static struct omap_hwmod am33xx_debugss_hwmod = {
>>> -       .name           = "debugss",
>>> -       .class          = &am33xx_debugss_hwmod_class,
>>> -       .clkdm_name     = "l3_aon_clkdm",
>>> -       .main_clk       = "debugss_ick",
>>> -       .prcm           = {
>>> -               .omap4  = {
>>> -                       .clkctrl_offs   = AM33XX_CM_WKUP_DEBUGSS_CLKCTRL_OFFSET,
>>> -                       .modulemode     = MODULEMODE_SWCTRL,
>>> -               },
>>> -       },
>>> -};
>>> -
>>> /* ocmcram */
>>>  static struct omap_hwmod_class am33xx_ocmcram_hwmod_class = {
>>>         .name = "ocmcram",
>>> @@ -570,6 +549,28 @@ static struct omap_hwmod am33xx_sha0_hwmod = {
>>>
>>>  #endif
>>>
>>> +/*
>>> + * 'debugss' class
>>> + * debug sub system
>>> + */
>>> +static struct omap_hwmod_class am33xx_debugss_hwmod_class = {
>>> +       .name           = "debugss",
>>> +};
>>> +
>>> +static struct omap_hwmod am33xx_debugss_hwmod = {
>>> +       .name           = "debugss",
>>> +       .class          = &am33xx_debugss_hwmod_class,
>>> +       .clkdm_name     = "l3_aon_clkdm",
>>> +       .main_clk       = "debugss_ick",
>>> +       .flags          =  (HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET),

Setting these flags would still leave the problem where JTAG clocks
are on when its not required no? In that case, what is the advantage
of this patch?


Regards,

Joel

RE: AM335x: Beaglebone stops to boot with current git kernel

[Hiremath, Vaibhav]

On Fri, Nov 23, 2012 at 02:26:40, Joel A Fernandes wrote:
> Hi Vaibhav, Igor,
> 
> On and off due to vacation time too,..
> 
> Not sure but I missed the below patch from Vaibhav as it probably
> wasn't copied to linux-omap so I got confused which patch was Igor
> testing, whether it was the one in which we set ENABLE_ON_INIT or the
> one in which hwmod data is changed.
> 
> I think Igor tried the latter and it works. In that case, I guess we
> can drop the ENABLE_ON_INIT patch if this is a better fix. I had some
> comments though...
> 


Let try to explain why we should go with hwmod patches,

When I submitted clock tree patch, we decided to remove all leaf-nodes from 
the data, but since modules like debugs were not enabled in hwmod (as done 
for omap) I had explicitly keep these nodes in clock-tree to disable them 
with RESET_CLOCKS flag.
Please refer to the comment in file clock33xx_data.c


567 /*
568  * Modules clock nodes
569  *
570  * The following clock leaf nodes are added for the moment because:
571  *
572  *  - hwmod data is not present for these modules, either hwmod
573  *    control is not required or its not populated.
574  *  - Driver code is not yet migrated to use hwmod/runtime pm
575  *  - Modules outside kernel access (to disable them by default)
576  *
577  *     - debugss
578  *     - mmu (gfx domain)
579  *     - cefuse
580  *     - usbotg_fck (its additional clock and not really a modulemode)
581  *     - ieee5000
582  */



Ideally (and to keep consistency with existing implementation), we should 
enable hwmod node and remove clock-tree node.


> On Thu, Nov 22, 2012 at 10:40 AM, Igor Mazanov <i.mazanov@gmail.com> wrote:
> > On Thu, Nov 22, 2012 at 6:49 PM, Hiremath, Vaibhav <hvaibhav@ti.com> wrote:
> [..]
> >>> I have quickly created patch for you, can you try below patch and let me
> >>> know?
> >>>
> >>>
> >>>
> >>> diff --git a/arch/arm/mach-omap2/cclock33xx_data.c b/arch/arm/mach-omap2/cclock33xx_data.c
> >>> index ea64ad6..c9af78c 100644
> >>> --- a/arch/arm/mach-omap2/cclock33xx_data.c
> >>> +++ b/arch/arm/mach-omap2/cclock33xx_data.c
> >>> @@ -920,6 +920,7 @@ static const char *enable_init_clks[] = {
> >>>         "l4hs_gclk",
> >>>         "l4fw_gclk",
> >>>         "l4ls_gclk",
> >>> +       "debugss_ick",
> >>>  };
> >>>
> >>>  int __init am33xx_clk_init(void)
> >>> diff --git a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
> >>> index ad8d43b..750b897 100644
> >>> --- a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
> >>> +++ b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
> >>> @@ -460,27 +460,6 @@ static struct omap_hwmod am33xx_clkdiv32k_hwmod = {
> >>>         },
> >>>  };
> >>>
> >>> -/*
> >>> - * 'debugss' class
> >>> - * debug sub system
> >>> - */
> >>> -static struct omap_hwmod_class am33xx_debugss_hwmod_class = {
> >>> -       .name           = "debugss",
> >>> -};
> >>> -
> >>> -static struct omap_hwmod am33xx_debugss_hwmod = {
> >>> -       .name           = "debugss",
> >>> -       .class          = &am33xx_debugss_hwmod_class,
> >>> -       .clkdm_name     = "l3_aon_clkdm",
> >>> -       .main_clk       = "debugss_ick",
> >>> -       .prcm           = {
> >>> -               .omap4  = {
> >>> -                       .clkctrl_offs   = AM33XX_CM_WKUP_DEBUGSS_CLKCTRL_OFFSET,
> >>> -                       .modulemode     = MODULEMODE_SWCTRL,
> >>> -               },
> >>> -       },
> >>> -};
> >>> -
> >>> /* ocmcram */
> >>>  static struct omap_hwmod_class am33xx_ocmcram_hwmod_class = {
> >>>         .name = "ocmcram",
> >>> @@ -570,6 +549,28 @@ static struct omap_hwmod am33xx_sha0_hwmod = {
> >>>
> >>>  #endif
> >>>
> >>> +/*
> >>> + * 'debugss' class
> >>> + * debug sub system
> >>> + */
> >>> +static struct omap_hwmod_class am33xx_debugss_hwmod_class = {
> >>> +       .name           = "debugss",
> >>> +};
> >>> +
> >>> +static struct omap_hwmod am33xx_debugss_hwmod = {
> >>> +       .name           = "debugss",
> >>> +       .class          = &am33xx_debugss_hwmod_class,
> >>> +       .clkdm_name     = "l3_aon_clkdm",
> >>> +       .main_clk       = "debugss_ick",
> >>> +       .flags          =  (HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET),
> 
> Setting these flags would still leave the problem where JTAG clocks
> are on when its not required no? In that case, what is the advantage
> of this patch?
> 

I missed to wrap it around #ifdef CONFIG_DEBUG_KERNEL. I will submit the 
formal patch shortly.

Thanks,
Vaibhav

RE: AM335x: Beaglebone stops to boot with current git kernel

[Hiremath, Vaibhav]

On Thu, Nov 22, 2012 at 22:10:07, Igor Mazanov wrote:
> On Thu, Nov 22, 2012 at 6:49 PM, Hiremath, Vaibhav <hvaibhav@ti.com> wrote:
> > On Thu, Nov 22, 2012 at 20:17:26, Hiremath, Vaibhav wrote:
> >> On Thu, Nov 22, 2012 at 17:46:50, Igor Mazanov wrote:
> >> > On Thu, Nov 22, 2012 at 9:42 AM, Vaibhav Hiremath <hvaibhav@ti.com> wrote:
> >> > >
> >> > >
> >> > > On 11/22/2012 1:30 AM, Igor Mazanov wrote:
> >> > >> On Wed, Nov 21, 2012 at 9:38 PM, Tony Lindgren <tony@atomide.com> wrote:
> >> > >>> * Jean Pihet <jean.pihet@newoldbits.com> [121114 08:43]:
> >> > >>>> On Wed, Nov 14, 2012 at 4:28 PM, Igor Mazanov <i.mazanov@gmail.com> wrote:
> >> > >>>>>
> >> > >>>>> Beaglebone boot process is broken with the current git kernel. I use
> >> > >>>>> omap2plus_defconfig for tests.
> >> > >>>>>
> >> > >>>>> It looks like the boot process stops due to the last changes in the AM33xx
> >> > >>>>> clock sysbsystem. A following patch resolves this issue:
> >> > >>> ...
> >> > >>>
> >> > >>>> The patch should change the name of the hwmod entry as well, can you
> >> > >>>> fold this change in the current patch?
> >> > >>>
> >> > >>> Any news on updating this?
> >> > >>
> >> > >> The current kernel boots, but after a switching to CCF doesn't work
> >> > >> the debugss - it's just disabled in the current hwmod code. So, it
> >> > >> looks like we can't  use JTAG to connect to the running kernel.
> >> > >>
> >> > >
> >> > > just resumed from vacation...
> >> > >
> >> > > JTAG clock will get disabled because, CONFIG_OMAP_RESET_CLOCKS will
> >> > > disable unused clocks, so as debugss clock.
> >> > >
> >> > > There is another thread started by Joel on the similar issue,
> >> > >
> >> > > http://www.mail-archive.com/linux-omap@vger.kernel.org/msg80863.html
> >> > >
> >> > > Something below should be done for debugss on AM33xx,
> >> > >
> >> > > diff --git a/arch/arm/mach-omap2/clock33xx_data.c
> >> > > b/arch/arm/mach-omap2/clock33xx_data.c
> >> > > index 17e3de5..60e0b53 100644
> >> > > --- a/arch/arm/mach-omap2/clock33xx_data.c
> >> > > +++ b/arch/arm/mach-omap2/clock33xx_data.c
> >> > > @@ -584,6 +584,9 @@ static struct clk debugss_ick = {
> >> > >         .clkdm_name     = "l3_aon_clkdm",
> >> > >         .parent         = &dpll_core_m4_ck,
> >> > >         .ops            = &clkops_omap2_dflt,
> >> > > +#ifdef CONFIG_DEBUG_KERNEL
> >> > > +       .flags          = ENABLE_ON_INIT,
> >> > > +#endif
> >> > >         .enable_reg     = AM33XX_CM_WKUP_DEBUGSS_CLKCTRL,
> >> > >         .enable_bit     = AM33XX_MODULEMODE_SWCTRL,
> >> > >         .recalc         = &followparent_recalc,
> >> >
> >> > Yes, I noticed this thread. But now a clock subsystem in the current
> >> > kernel is switched to Common Clock Framework and debugss (and several
> >> > another modules) is disabled
> >>
> >> Still this can be handled and enabled during init.
> >>
> >>
> >> > (#if 0 .... #endif) in
> >> > omap_hwmod_33xx_data.c.
> >> >
> >> > From omap_hwmod_33xx_data.c:
> >> >
> >> > /*
> >> >  * Modules omap_hwmod structures
> >> >  *
> >> >  * The following IPs are excluded for the moment because:
> >> >  * - They do not need an explicit SW control using omap_hwmod API.
> >> >  * - They still need to be validated with the driver
> >> >  *   properly adapted to omap_hwmod / omap_device
> >> >  *
> >> >  *    - cEFUSE (doesn't fall under any ocp_if)
> >> >  *    - clkdiv32k
> >> >  *    - debugss
> >> >  *    - ocmc ram
> >> >  *    - ocp watch point
> >> >  *    - aes0
> >> >  *    - sha0
> >> >  */
> >> >
> >> > I uncommented the debugss entry in the omap_hwmod settings, but only
> >> > got a warning like:
> >> >
> >> >  CC      arch/arm/mach-omap2/omap_hwmod_33xx_data.o
> >> > arch/arm/mach-omap2/omap_hwmod_33xx_data.c:472:26: warning:
> >> > 'am33xx_debugss_hwmod' defined but not used [-Wunused-variable]
> >> >
> >> > By the way, I need to use JTAG to trace a problem described in this thread:
> >> >
> >> > http://marc.info/?l=linux-omap&m=135307646415429&w=2
> >> >
> >> > May be, it's the clocks related issue too...
> >> >
> >>
> >>
> >> I have quickly created patch for you, can you try below patch and let me
> >> know?
> >>
> >>
> >>
> >> diff --git a/arch/arm/mach-omap2/cclock33xx_data.c b/arch/arm/mach-omap2/cclock33xx_data.c
> >> index ea64ad6..c9af78c 100644
> >> --- a/arch/arm/mach-omap2/cclock33xx_data.c
> >> +++ b/arch/arm/mach-omap2/cclock33xx_data.c
> >> @@ -920,6 +920,7 @@ static const char *enable_init_clks[] = {
> >>         "l4hs_gclk",
> >>         "l4fw_gclk",
> >>         "l4ls_gclk",
> >> +       "debugss_ick",
> >>  };
> >>
> >>  int __init am33xx_clk_init(void)
> >> diff --git a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
> >> index ad8d43b..750b897 100644
> >> --- a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
> >> +++ b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
> >> @@ -460,27 +460,6 @@ static struct omap_hwmod am33xx_clkdiv32k_hwmod = {
> >>         },
> >>  };
> >>
> >> -/*
> >> - * 'debugss' class
> >> - * debug sub system
> >> - */
> >> -static struct omap_hwmod_class am33xx_debugss_hwmod_class = {
> >> -       .name           = "debugss",
> >> -};
> >> -
> >> -static struct omap_hwmod am33xx_debugss_hwmod = {
> >> -       .name           = "debugss",
> >> -       .class          = &am33xx_debugss_hwmod_class,
> >> -       .clkdm_name     = "l3_aon_clkdm",
> >> -       .main_clk       = "debugss_ick",
> >> -       .prcm           = {
> >> -               .omap4  = {
> >> -                       .clkctrl_offs   = AM33XX_CM_WKUP_DEBUGSS_CLKCTRL_OFFSET,
> >> -                       .modulemode     = MODULEMODE_SWCTRL,
> >> -               },
> >> -       },
> >> -};
> >> -
> >> /* ocmcram */
> >>  static struct omap_hwmod_class am33xx_ocmcram_hwmod_class = {
> >>         .name = "ocmcram",
> >> @@ -570,6 +549,28 @@ static struct omap_hwmod am33xx_sha0_hwmod = {
> >>
> >>  #endif
> >>
> >> +/*
> >> + * 'debugss' class
> >> + * debug sub system
> >> + */
> >> +static struct omap_hwmod_class am33xx_debugss_hwmod_class = {
> >> +       .name           = "debugss",
> >> +};
> >> +
> >> +static struct omap_hwmod am33xx_debugss_hwmod = {
> >> +       .name           = "debugss",
> >> +       .class          = &am33xx_debugss_hwmod_class,
> >> +       .clkdm_name     = "l3_aon_clkdm",
> >> +       .main_clk       = "debugss_ick",
> >> +       .flags          =  (HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET),
> >> +       .prcm           = {
> >> +               .omap4  = {
> >> +                       .clkctrl_offs   = AM33XX_CM_WKUP_DEBUGSS_CLKCTRL_OFFSET,
> >> +                       .modulemode     = MODULEMODE_SWCTRL,
> >> +               },
> >> +       },
> >> +};
> >> +
> >>  /* 'smartreflex' class */
> >>  static struct omap_hwmod_class am33xx_smartreflex_hwmod_class = {
> >>         .name           = "smartreflex",
> >> @@ -2261,6 +2262,24 @@ static struct omap_hwmod_ocp_if am33xx_l3_main__gfx = {
> >>         .user           = OCP_USER_MPU | OCP_USER_SDMA,
> >>  };
> >>
> >> +/* l3_main -> debugss */
> >> +static struct omap_hwmod_addr_space am33xx_debugss_addrs[] = {
> >> +       {
> >> +               .pa_start       = 0x4b000000,
> >> +               .pa_end         = 0x4b000000 + SZ_16M - 1,
> >> +               .flags          = ADDR_TYPE_RT
> >> +       },
> >> +       { }
> >> +};
> >> +
> >> +static struct omap_hwmod_ocp_if am33xx_l3_main__debugss = {
> >> +       .master         = &am33xx_l3_main_hwmod,
> >> +       .slave          = &am33xx_debugss_hwmod,
> >> +       .clk            = "debugss_ick",
> >> +       .addr           = am33xx_debugss_addrs,
> >> +       .user           = OCP_USER_MPU,
> >> +};
> >> +
> >>  /* l4 wkup -> smartreflex0 */
> >>  static struct omap_hwmod_addr_space am33xx_smartreflex0_addrs[] = {
> >>         {
> >> @@ -3315,6 +3334,7 @@ static struct omap_hwmod_ocp_if *am33xx_hwmod_ocp_ifs[] __initdata = {
> >>         &am33xx_pruss__l3_main,
> >>         &am33xx_wkup_m3__l4_wkup,
> >>         &am33xx_gfx__l3_main,
> >> +       &am33xx_l3_main__debugss,
> >>         &am33xx_l4_wkup__wkup_m3,
> >>         &am33xx_l4_wkup__control,
> >>         &am33xx_l4_wkup__smartreflex0,
> >>
> >>
> >
> >
> >
> > Missed to mention that,
> >
> > I have boot tested it on Bone platform and made sure that debugs module
> > stays enabled after boot (after applying this patch).
> >
> 
> I applied your patch and it works for me too. JTAG interface is
> working now. Thanks!
> 

Thanks Igor,

I will submit formal patch shortly, care to test and review/ack it.

Thanks,
Vaibhav 

Re: AM335x: Beaglebone stops to boot with current git kernel

[Kevin Hilman]

"Hiremath, Vaibhav" <hvaibhav@ti.com> writes:

>> >>> +static struct omap_hwmod am33xx_debugss_hwmod = {
>> >>> +       .name           = "debugss",
>> >>> +       .class          = &am33xx_debugss_hwmod_class,
>> >>> +       .clkdm_name     = "l3_aon_clkdm",
>> >>> +       .main_clk       = "debugss_ick",
>> >>> +       .flags          =  (HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET),
>> 
>> Setting these flags would still leave the problem where JTAG clocks
>> are on when its not required no? In that case, what is the advantage
>> of this patch?
>> 
>
> I missed to wrap it around #ifdef CONFIG_DEBUG_KERNEL. I will submit the 
> formal patch shortly.

IMO, this should not be handled in the data at all (neither clock nor
hwmod), and should be handled at runtime/boot-time, not compile time.

The solution to this is to rather to have a small bit of code that
requests the debugss clocks that are needed for JTAG debug, so the
kernel knows they are in use.

That code could then be enabled at boot time via command-line or DT
option.

Kevin

RE: AM335x: Beaglebone stops to boot with current git kernel

[Hiremath, Vaibhav]

On Mon, Dec 03, 2012 at 23:49:36, Kevin Hilman wrote:
> "Hiremath, Vaibhav" <hvaibhav@ti.com> writes:
> 
> >> >>> +static struct omap_hwmod am33xx_debugss_hwmod = {
> >> >>> +       .name           = "debugss",
> >> >>> +       .class          = &am33xx_debugss_hwmod_class,
> >> >>> +       .clkdm_name     = "l3_aon_clkdm",
> >> >>> +       .main_clk       = "debugss_ick",
> >> >>> +       .flags          =  (HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET),
> >> 
> >> Setting these flags would still leave the problem where JTAG clocks
> >> are on when its not required no? In that case, what is the advantage
> >> of this patch?
> >> 
> >
> > I missed to wrap it around #ifdef CONFIG_DEBUG_KERNEL. I will submit the 
> > formal patch shortly.
> 
> IMO, this should not be handled in the data at all (neither clock nor
> hwmod), and should be handled at runtime/boot-time, not compile time.
> 

Wouldn't that become another interface/control for debug? We already have 
various (standard) debug kernel parameters available.

But I see your point, compile-time option will force users to rebuild kernel 
just in order to disable JTAG/Debug clock.

> The solution to this is to rather to have a small bit of code that
> requests the debugss clocks that are needed for JTAG debug, so the
> kernel knows they are in use.
> 
> That code could then be enabled at boot time via command-line or DT
> option.
> 

In case of command-line, something like below???

static int __init omap2_debug_clk_enable(char *str)
{
	if (!str)
		return 0;
	
	if (!strcmp(str, "debug"))
		<enable debug clock>

	return 0;
}
early_param("debug", omap2_debug_clk_enable);


In case of DT, one thought,

It can be part of omap_generic_init() in board-generic.c file,
We can parse there for debug node and required property to enable debug 
module.

Any thought? Or Other options???

Thanks,
Vaibhav

Re: AM335x: Beaglebone stops to boot with current git kernel

[Joel A Fernandes]

On Mon, Dec 3, 2012 at 10:01 PM, Hiremath, Vaibhav <hvaibhav@ti.com> wrote:
>
> On Mon, Dec 03, 2012 at 23:49:36, Kevin Hilman wrote:
> > "Hiremath, Vaibhav" <hvaibhav@ti.com> writes:
> >
> > >> >>> +static struct omap_hwmod am33xx_debugss_hwmod = {
> > >> >>> +       .name           = "debugss",
> > >> >>> +       .class          = &am33xx_debugss_hwmod_class,
> > >> >>> +       .clkdm_name     = "l3_aon_clkdm",
> > >> >>> +       .main_clk       = "debugss_ick",
> > >> >>> +       .flags          =  (HWMOD_INIT_NO_IDLE |
> > >> >>> HWMOD_INIT_NO_RESET),
> > >>
> > >> Setting these flags would still leave the problem where JTAG clocks
> > >> are on when its not required no? In that case, what is the advantage
> > >> of this patch?
> > >>
> > >
> > > I missed to wrap it around #ifdef CONFIG_DEBUG_KERNEL. I will submit
> > > the
> > > formal patch shortly.
> >
> > IMO, this should not be handled in the data at all (neither clock nor
> > hwmod), and should be handled at runtime/boot-time, not compile time.
> >
>
> Wouldn't that become another interface/control for debug? We already have
> various (standard) debug kernel parameters available.
>
> But I see your point, compile-time option will force users to rebuild
> kernel
> just in order to disable JTAG/Debug clock.
>
> > The solution to this is to rather to have a small bit of code that
> > requests the debugss clocks that are needed for JTAG debug, so the
> > kernel knows they are in use.
> >
> > That code could then be enabled at boot time via command-line or DT
> > option.
> >
>
> In case of command-line, something like below???
>
> static int __init omap2_debug_clk_enable(char *str)
> {
>         if (!str)
>                 return 0;
>
>         if (!strcmp(str, "debug"))
>                 <enable debug clock>
>
>         return 0;
> }
> early_param("debug", omap2_debug_clk_enable);
>

This approach looks , I wrote similar code replacing "enable debug clock" with:

jtag_clk = clk_get(NULL, "debugss_ick");
if(!IS_ERR_OR_NULL(jtag_clk))
  clk_enable(jtag_clk);

>
> In case of DT, one thought,
>
> It can be part of omap_generic_init() in board-generic.c file,
> We can parse there for debug node and required property to enable debug
> module.
>
> Any thought? Or Other options???

Not sure, but can we append to bootargs from DT itself thus the above
cmdline code can be used to enable debugss for both regular bootargs
as well DT?

Regards,
Joel

Re: AM335x: Beaglebone stops to boot with current git kernel

[Kevin Hilman]

"Hiremath, Vaibhav" <hvaibhav@ti.com> writes:

> On Mon, Dec 03, 2012 at 23:49:36, Kevin Hilman wrote:
>> "Hiremath, Vaibhav" <hvaibhav@ti.com> writes:
>> 
>> >> >>> +static struct omap_hwmod am33xx_debugss_hwmod = {
>> >> >>> +       .name           = "debugss",
>> >> >>> +       .class          = &am33xx_debugss_hwmod_class,
>> >> >>> +       .clkdm_name     = "l3_aon_clkdm",
>> >> >>> +       .main_clk       = "debugss_ick",
>> >> >>> +       .flags          =  (HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET),
>> >> 
>> >> Setting these flags would still leave the problem where JTAG clocks
>> >> are on when its not required no? In that case, what is the advantage
>> >> of this patch?
>> >> 
>> >
>> > I missed to wrap it around #ifdef CONFIG_DEBUG_KERNEL. I will submit the 
>> > formal patch shortly.
>> 
>> IMO, this should not be handled in the data at all (neither clock nor
>> hwmod), and should be handled at runtime/boot-time, not compile time.
>> 
>
> Wouldn't that become another interface/control for debug? We already have 
> various (standard) debug kernel parameters available.
>
> But I see your point, compile-time option will force users to rebuild kernel 
> just in order to disable JTAG/Debug clock.
>
>> The solution to this is to rather to have a small bit of code that
>> requests the debugss clocks that are needed for JTAG debug, so the
>> kernel knows they are in use.
>> 
>> That code could then be enabled at boot time via command-line or DT
>> option.
>> 
>
> In case of command-line, something like below???
>
> static int __init omap2_debug_clk_enable(char *str)
> {
> 	if (!str)
> 		return 0;
> 	
> 	if (!strcmp(str, "debug"))
> 		<enable debug clock>
>
> 	return 0;
> }
> early_param("debug", omap2_debug_clk_enable);

Yes, that's the idea I had in mind.  Though you don't want to override
"debug" here.  The debug option is specifically about default log levels
for the console and isn't really related to clocks.

Kevin