* [PATCH] ARM: OMAP2+: don't try to register the main clock twice.
@ 2014-03-28 11:50 Wolfram Sang
2014-04-11 18:33 ` Paul Walmsley
0 siblings, 1 reply; 5+ messages in thread
From: Wolfram Sang @ 2014-03-28 11:50 UTC (permalink / raw)
To: linux-omap
Cc: Benoit Cousson, Tony Lindgren, Paul Walmsley, NeilBrown, Wolfram Sang
From: NeilBrown <neilb@suse.de>
If omap_device_alloc is given 2 or more "struct omap_hwmod" it will try
to register the 'main_clk' of each of them with the same alias - "fck" -
against the same device. This fails. So to avoid a warning, don't even
try.
Signed-off-by: NeilBrown <neilb@suse.de>
[wsa: ported to top-of-tree]
Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
---
Digged this out from the net and think this makes sense. I am going to use it
with an AM335x based board. Based on v3.14-rc8.
arch/arm/mach-omap2/omap_device.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c
index 01ef59def44b..ce132d0084d2 100644
--- a/arch/arm/mach-omap2/omap_device.c
+++ b/arch/arm/mach-omap2/omap_device.c
@@ -84,6 +84,7 @@ static void _add_clkdev(struct omap_device *od, const char *clk_alias,
* and main clock
* @od: struct omap_device *od
* @oh: struct omap_hwmod *oh
+ * @sub: if > 0, this is a subordinate device, so don't try to register fck
*
* For the main clock and every optional clock present per hwmod per
* omap_device, this function adds an entry in the clkdev table of the
@@ -99,11 +100,12 @@ static void _add_clkdev(struct omap_device *od, const char *clk_alias,
* No return value.
*/
static void _add_hwmod_clocks_clkdev(struct omap_device *od,
- struct omap_hwmod *oh)
+ struct omap_hwmod *oh, int sub)
{
int i;
- _add_clkdev(od, "fck", oh->main_clk);
+ if (!sub)
+ _add_clkdev(od, "fck", oh->main_clk);
for (i = 0; i < oh->opt_clks_cnt; i++)
_add_clkdev(od, oh->opt_clks[i].role, oh->opt_clks[i].clk);
@@ -468,7 +470,7 @@ have_everything:
for (i = 0; i < oh_cnt; i++) {
hwmods[i]->od = od;
- _add_hwmod_clocks_clkdev(od, hwmods[i]);
+ _add_hwmod_clocks_clkdev(od, hwmods[i], i);
}
return od;
--
1.9.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] ARM: OMAP2+: don't try to register the main clock twice.
2014-03-28 11:50 [PATCH] ARM: OMAP2+: don't try to register the main clock twice Wolfram Sang
@ 2014-04-11 18:33 ` Paul Walmsley
2014-04-17 8:55 ` Wolfram Sang
0 siblings, 1 reply; 5+ messages in thread
From: Paul Walmsley @ 2014-04-11 18:33 UTC (permalink / raw)
To: Wolfram Sang, NeilBrown
Cc: linux-omap, Benoit Cousson, Tony Lindgren, Wolfram Sang
Hi Wolfram, Neil,
On Fri, 28 Mar 2014, Wolfram Sang wrote:
> From: NeilBrown <neilb@suse.de>
>
> If omap_device_alloc is given 2 or more "struct omap_hwmod" it will try
> to register the 'main_clk' of each of them with the same alias - "fck" -
> against the same device. This fails. So to avoid a warning, don't even
> try.
>
> Signed-off-by: NeilBrown <neilb@suse.de>
> [wsa: ported to top-of-tree]
> Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
What devices and hwmods cause this warning on AM335x? Ideally, there
should only be one hwmod per device. Usually when multiple hwmods are
stacked up for a device, it means that something isn't right - either the
hwmod data, or the device driver itself.
In the specific context of this patch, the problem would be: what if the
two hwmods have different main_clk entries? Which one should be
associated with the "fck" alias?
- Paul
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] ARM: OMAP2+: don't try to register the main clock twice.
2014-04-11 18:33 ` Paul Walmsley
@ 2014-04-17 8:55 ` Wolfram Sang
2014-05-07 23:20 ` Paul Walmsley
0 siblings, 1 reply; 5+ messages in thread
From: Wolfram Sang @ 2014-04-17 8:55 UTC (permalink / raw)
To: Paul Walmsley
Cc: NeilBrown, linux-omap, Benoit Cousson, Tony Lindgren, Wolfram Sang
[-- Attachment #1: Type: text/plain, Size: 1404 bytes --]
Hi Paul,
thanks for the reply!
> > If omap_device_alloc is given 2 or more "struct omap_hwmod" it will try
> > to register the 'main_clk' of each of them with the same alias - "fck" -
> > against the same device. This fails. So to avoid a warning, don't even
> > try.
> >
> > Signed-off-by: NeilBrown <neilb@suse.de>
> > [wsa: ported to top-of-tree]
> > Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
>
> What devices and hwmods cause this warning on AM335x? Ideally, there
> should only be one hwmod per device. Usually when multiple hwmods are
> stacked up for a device, it means that something isn't right - either the
> hwmod data, or the device driver itself.
I applied the patch because of the edma driver DT entry for the am335x.
Check am33xx.dtsi, it has multiple hwmods. I also get this message
printed for the d_can driver with am335x; they have two entries in
drivers/clk/ti/clk-33xx.c. Probably as a workaround to match the desired
clock name for the d_can driver? Didn't really investigate yet.
> In the specific context of this patch, the problem would be: what if the
> two hwmods have different main_clk entries? Which one should be
> associated with the "fck" alias?
Sadly, I am in a board bringup phase and can't really contribute to the
discussions. Lots of other issues to tackle at the moment.
All the best,
Wolfram
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] ARM: OMAP2+: don't try to register the main clock twice.
2014-04-17 8:55 ` Wolfram Sang
@ 2014-05-07 23:20 ` Paul Walmsley
2014-05-08 7:02 ` Wolfram Sang
0 siblings, 1 reply; 5+ messages in thread
From: Paul Walmsley @ 2014-05-07 23:20 UTC (permalink / raw)
To: Wolfram Sang, mporter, Benoit Cousson, joelagnel
Cc: NeilBrown, linux-omap, Tony Lindgren, Wolfram Sang
(+ Matt Porter, Joel Fernandes)
Hi Wolfram,
On Thu, 17 Apr 2014, Wolfram Sang wrote:
> thanks for the reply!
Always good to hear from you -
> > > If omap_device_alloc is given 2 or more "struct omap_hwmod" it will try
> > > to register the 'main_clk' of each of them with the same alias - "fck" -
> > > against the same device. This fails. So to avoid a warning, don't even
> > > try.
> > >
> > > Signed-off-by: NeilBrown <neilb@suse.de>
> > > [wsa: ported to top-of-tree]
> > > Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
> >
> > What devices and hwmods cause this warning on AM335x? Ideally, there
> > should only be one hwmod per device. Usually when multiple hwmods are
> > stacked up for a device, it means that something isn't right - either the
> > hwmod data, or the device driver itself.
>
> I applied the patch because of the edma driver DT entry for the am335x.
> Check am33xx.dtsi, it has multiple hwmods.
I just took a look at the EDMA DT data vis-a-vis SPRUH73J Section 11.2.2
"Third-Party Transfer Controller (TPTC) Integration". This section
clearly indicates that the TPTCs have their own L3 Fast Interconnect slave
ports, marked as "CFG Slave". Cross-checking this with Table 2-1 "L3
Memory Map" indeed indicates that these three devices have their own 1MB
physical address ranges hanging off the L3.
So the EDMA DT data is flat-out wrong here and should not have been
merged. Looks like it was added by commit
505975d3802f8d3a3c0905f38056213d06997b36 ("ARM: dts: AM33XX: Add EDMA
support"). Matt, Joel, could you please fix this data? The TPTCs are
separate IP blocks with separate address ranges and MPU IRQs and should
have separate DT nodes.
> I also get this message printed for the d_can driver with am335x; they
> have two entries in drivers/clk/ti/clk-33xx.c. Probably as a workaround
> to match the desired clock name for the d_can driver? Didn't really
> investigate yet.
That's pretty weird. I wonder where the second fck alias is coming from?
The DT & hwmod data for those devices looks relatively straightforward.
Is the hwmod code adding fck aliases for both of the entries from the
clock file?
> > In the specific context of this patch, the problem would be: what if the
> > two hwmods have different main_clk entries? Which one should be
> > associated with the "fck" alias?
>
> Sadly, I am in a board bringup phase and can't really contribute to the
> discussions. Lots of other issues to tackle at the moment.
Understood. Good luck with your board -
- Paul
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] ARM: OMAP2+: don't try to register the main clock twice.
2014-05-07 23:20 ` Paul Walmsley
@ 2014-05-08 7:02 ` Wolfram Sang
0 siblings, 0 replies; 5+ messages in thread
From: Wolfram Sang @ 2014-05-08 7:02 UTC (permalink / raw)
To: Paul Walmsley
Cc: mporter, Benoit Cousson, joelagnel, NeilBrown, linux-omap,
Tony Lindgren, Wolfram Sang
[-- Attachment #1: Type: text/plain, Size: 984 bytes --]
> > I also get this message printed for the d_can driver with am335x; they
> > have two entries in drivers/clk/ti/clk-33xx.c. Probably as a workaround
> > to match the desired clock name for the d_can driver? Didn't really
> > investigate yet.
>
> That's pretty weird. I wonder where the second fck alias is coming from?
> The DT & hwmod data for those devices looks relatively straightforward.
> Is the hwmod code adding fck aliases for both of the entries from the
> clock file?
$ grep 'can' drivers/clk/ti/clk-33xx.c
* This program is free software; you can redistribute it and/or
DT_CLK(NULL, "dcan0_fck", "dcan0_fck"),
DT_CLK("481cc000.d_can", NULL, "dcan0_fck"),
DT_CLK(NULL, "dcan1_fck", "dcan1_fck"),
DT_CLK("481d0000.d_can", NULL, "dcan1_fck"),
I quickly tried to remove the entries not specifying platform devices
but that prevented my system from booting (Huh?). Still, no time to
really check it, though.
Thanks,
Wolfram
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^ permalink raw reply [flat|nested] 5+ messages in thread
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-- links below jump to the message on this page --
2014-03-28 11:50 [PATCH] ARM: OMAP2+: don't try to register the main clock twice Wolfram Sang
2014-04-11 18:33 ` Paul Walmsley
2014-04-17 8:55 ` Wolfram Sang
2014-05-07 23:20 ` Paul Walmsley
2014-05-08 7:02 ` Wolfram Sang
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