* [PATCH v5] mmc: sdhci: clarify the get_timeout_clock callback
@ 2017-03-17 3:11 Shawn Lin
2017-03-24 7:40 ` Ulf Hansson
0 siblings, 1 reply; 3+ messages in thread
From: Shawn Lin @ 2017-03-17 3:11 UTC (permalink / raw)
To: Adrian Hunter, Ulf Hansson
Cc: linux-mmc, Masahiro Yamada, Shawn Lin, Anssi Hannula
Currently the get_timeout_clock callback doesn't clearly
have a statement that it needs the variant drivers to return
the timeout clock rate in kHz if the SDHCI_TIMEOUT_CLK_UNIT
isn't present, otherwise the variant drivers should return it
in MHz. So actually sdhci-of-arasan return the wrong value found
by Anssi[1]. It's also very likely that further variant drivers which
are going to use this callback will be confused by this situation.
Given the fact that moderm sdhci variant hosts are very prone to get
the timeout clock from common clock framework (actually the only three
users did that), it's more natural to return the value in Hz and we
make an explicit comment there. Then we put the unit conversion inside
the sdhci core. Thus will improve the code and prevent further misuses.
[1]: https://patchwork.kernel.org/patch/9569431/
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Anssi Hannula <anssi.hannula@bitwise.fi>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---
Changes in v5:
- fix typo
- remove unlikely
Changes in v4:
- rebased on -next
- add Masahiro's ack for sdhci-cadence
Changes in v3:
- squash all the patches into one to keep bisectability
- fix wrong return value of sdhci-cadence
- slight improve the condition check to avoid the complaint of
checkpatch
Changes in v2:
- fix the comment and make it return in Hz
drivers/mmc/host/sdhci-cadence.c | 4 ++--
drivers/mmc/host/sdhci-of-arasan.c | 17 +----------------
drivers/mmc/host/sdhci.c | 16 +++++++++-------
drivers/mmc/host/sdhci.h | 1 +
4 files changed, 13 insertions(+), 25 deletions(-)
diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
index 316cfec..7baeeaf 100644
--- a/drivers/mmc/host/sdhci-cadence.c
+++ b/drivers/mmc/host/sdhci-cadence.c
@@ -103,9 +103,9 @@ static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
{
/*
* Cadence's spec says the Timeout Clock Frequency is the same as the
- * Base Clock Frequency. Divide it by 1000 to return a value in kHz.
+ * Base Clock Frequency.
*/
- return host->max_clk / 1000;
+ return host->max_clk;
}
static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
index 1cfd7f9..c52f153 100644
--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c
@@ -157,21 +157,6 @@ static int sdhci_arasan_syscon_write(struct sdhci_host *host,
return ret;
}
-static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
-{
- unsigned long freq;
- struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
-
- /* SDHCI timeout clock is in kHz */
- freq = DIV_ROUND_UP(clk_get_rate(pltfm_host->clk), 1000);
-
- /* or in MHz */
- if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
- freq = DIV_ROUND_UP(freq, 1000);
-
- return freq;
-}
-
static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -286,7 +271,7 @@ static int sdhci_arasan_voltage_switch(struct mmc_host *mmc,
static struct sdhci_ops sdhci_arasan_ops = {
.set_clock = sdhci_arasan_set_clock,
.get_max_clock = sdhci_pltfm_clk_get_max_clock,
- .get_timeout_clock = sdhci_arasan_get_timeout_clock,
+ .get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
.set_bus_width = sdhci_set_bus_width,
.reset = sdhci_arasan_reset,
.set_uhs_signaling = sdhci_set_uhs_signaling,
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 6fdd7a7..4a9df4ac 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3289,20 +3289,22 @@ int sdhci_setup_host(struct sdhci_host *host)
if (!(host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)) {
host->timeout_clk = (host->caps & SDHCI_TIMEOUT_CLK_MASK) >>
SDHCI_TIMEOUT_CLK_SHIFT;
+
+ if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
+ host->timeout_clk *= 1000;
+
if (host->timeout_clk == 0) {
- if (host->ops->get_timeout_clock) {
- host->timeout_clk =
- host->ops->get_timeout_clock(host);
- } else {
+ if (!host->ops->get_timeout_clock) {
pr_err("%s: Hardware doesn't specify timeout clock frequency.\n",
mmc_hostname(mmc));
ret = -ENODEV;
goto undma;
}
- }
- if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
- host->timeout_clk *= 1000;
+ host->timeout_clk =
+ DIV_ROUND_UP(host->ops->get_timeout_clock(host),
+ 1000);
+ }
if (override_timeout_clk)
host->timeout_clk = override_timeout_clk;
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index edf3adf..27c252c 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -547,6 +547,7 @@ struct sdhci_ops {
int (*enable_dma)(struct sdhci_host *host);
unsigned int (*get_max_clock)(struct sdhci_host *host);
unsigned int (*get_min_clock)(struct sdhci_host *host);
+ /* get_timeout_clock should return clk rate in unit of Hz */
unsigned int (*get_timeout_clock)(struct sdhci_host *host);
unsigned int (*get_max_timeout_count)(struct sdhci_host *host);
void (*set_timeout)(struct sdhci_host *host,
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v5] mmc: sdhci: clarify the get_timeout_clock callback
2017-03-17 3:11 [PATCH v5] mmc: sdhci: clarify the get_timeout_clock callback Shawn Lin
@ 2017-03-24 7:40 ` Ulf Hansson
2017-03-24 7:43 ` Shawn Lin
0 siblings, 1 reply; 3+ messages in thread
From: Ulf Hansson @ 2017-03-24 7:40 UTC (permalink / raw)
To: Shawn Lin; +Cc: Adrian Hunter, linux-mmc, Masahiro Yamada, Anssi Hannula
On 17 March 2017 at 04:11, Shawn Lin <shawn.lin@rock-chips.com> wrote:
> Currently the get_timeout_clock callback doesn't clearly
> have a statement that it needs the variant drivers to return
> the timeout clock rate in kHz if the SDHCI_TIMEOUT_CLK_UNIT
> isn't present, otherwise the variant drivers should return it
> in MHz. So actually sdhci-of-arasan return the wrong value found
> by Anssi[1]. It's also very likely that further variant drivers which
> are going to use this callback will be confused by this situation.
> Given the fact that moderm sdhci variant hosts are very prone to get
> the timeout clock from common clock framework (actually the only three
> users did that), it's more natural to return the value in Hz and we
> make an explicit comment there. Then we put the unit conversion inside
> the sdhci core. Thus will improve the code and prevent further misuses.
>
> [1]: https://patchwork.kernel.org/patch/9569431/
>
> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: Anssi Hannula <anssi.hannula@bitwise.fi>
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Shawn, can you please re-base this as doesn't apply to my next branch.
While doing that, I would recommend to not refer to a patchwork link
in the changelog. It's better to do that in the section where you
describe the version history.
Instead I would add a "Reported-by: Anssi Hannula
<anssi.hannula@bitwise.fi>", to give Anssi cred about reporting the
issue.
Kind regards
Uffe
> ---
>
> Changes in v5:
> - fix typo
> - remove unlikely
>
> Changes in v4:
> - rebased on -next
> - add Masahiro's ack for sdhci-cadence
>
> Changes in v3:
> - squash all the patches into one to keep bisectability
> - fix wrong return value of sdhci-cadence
> - slight improve the condition check to avoid the complaint of
> checkpatch
>
> Changes in v2:
> - fix the comment and make it return in Hz
>
> drivers/mmc/host/sdhci-cadence.c | 4 ++--
> drivers/mmc/host/sdhci-of-arasan.c | 17 +----------------
> drivers/mmc/host/sdhci.c | 16 +++++++++-------
> drivers/mmc/host/sdhci.h | 1 +
> 4 files changed, 13 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
> index 316cfec..7baeeaf 100644
> --- a/drivers/mmc/host/sdhci-cadence.c
> +++ b/drivers/mmc/host/sdhci-cadence.c
> @@ -103,9 +103,9 @@ static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
> {
> /*
> * Cadence's spec says the Timeout Clock Frequency is the same as the
> - * Base Clock Frequency. Divide it by 1000 to return a value in kHz.
> + * Base Clock Frequency.
> */
> - return host->max_clk / 1000;
> + return host->max_clk;
> }
>
> static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index 1cfd7f9..c52f153 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -157,21 +157,6 @@ static int sdhci_arasan_syscon_write(struct sdhci_host *host,
> return ret;
> }
>
> -static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
> -{
> - unsigned long freq;
> - struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> -
> - /* SDHCI timeout clock is in kHz */
> - freq = DIV_ROUND_UP(clk_get_rate(pltfm_host->clk), 1000);
> -
> - /* or in MHz */
> - if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
> - freq = DIV_ROUND_UP(freq, 1000);
> -
> - return freq;
> -}
> -
> static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
> {
> struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> @@ -286,7 +271,7 @@ static int sdhci_arasan_voltage_switch(struct mmc_host *mmc,
> static struct sdhci_ops sdhci_arasan_ops = {
> .set_clock = sdhci_arasan_set_clock,
> .get_max_clock = sdhci_pltfm_clk_get_max_clock,
> - .get_timeout_clock = sdhci_arasan_get_timeout_clock,
> + .get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
> .set_bus_width = sdhci_set_bus_width,
> .reset = sdhci_arasan_reset,
> .set_uhs_signaling = sdhci_set_uhs_signaling,
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 6fdd7a7..4a9df4ac 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -3289,20 +3289,22 @@ int sdhci_setup_host(struct sdhci_host *host)
> if (!(host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)) {
> host->timeout_clk = (host->caps & SDHCI_TIMEOUT_CLK_MASK) >>
> SDHCI_TIMEOUT_CLK_SHIFT;
> +
> + if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
> + host->timeout_clk *= 1000;
> +
> if (host->timeout_clk == 0) {
> - if (host->ops->get_timeout_clock) {
> - host->timeout_clk =
> - host->ops->get_timeout_clock(host);
> - } else {
> + if (!host->ops->get_timeout_clock) {
> pr_err("%s: Hardware doesn't specify timeout clock frequency.\n",
> mmc_hostname(mmc));
> ret = -ENODEV;
> goto undma;
> }
> - }
>
> - if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
> - host->timeout_clk *= 1000;
> + host->timeout_clk =
> + DIV_ROUND_UP(host->ops->get_timeout_clock(host),
> + 1000);
> + }
>
> if (override_timeout_clk)
> host->timeout_clk = override_timeout_clk;
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index edf3adf..27c252c 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -547,6 +547,7 @@ struct sdhci_ops {
> int (*enable_dma)(struct sdhci_host *host);
> unsigned int (*get_max_clock)(struct sdhci_host *host);
> unsigned int (*get_min_clock)(struct sdhci_host *host);
> + /* get_timeout_clock should return clk rate in unit of Hz */
> unsigned int (*get_timeout_clock)(struct sdhci_host *host);
> unsigned int (*get_max_timeout_count)(struct sdhci_host *host);
> void (*set_timeout)(struct sdhci_host *host,
> --
> 1.9.1
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v5] mmc: sdhci: clarify the get_timeout_clock callback
2017-03-24 7:40 ` Ulf Hansson
@ 2017-03-24 7:43 ` Shawn Lin
0 siblings, 0 replies; 3+ messages in thread
From: Shawn Lin @ 2017-03-24 7:43 UTC (permalink / raw)
To: Ulf Hansson; +Cc: Adrian Hunter, linux-mmc, Masahiro Yamada, Anssi Hannula
Hi Ulf,
On 2017/3/24 15:40, Ulf Hansson wrote:
> On 17 March 2017 at 04:11, Shawn Lin <shawn.lin@rock-chips.com> wrote:
>> Currently the get_timeout_clock callback doesn't clearly
>> have a statement that it needs the variant drivers to return
>> the timeout clock rate in kHz if the SDHCI_TIMEOUT_CLK_UNIT
>> isn't present, otherwise the variant drivers should return it
>> in MHz. So actually sdhci-of-arasan return the wrong value found
>> by Anssi[1]. It's also very likely that further variant drivers which
>> are going to use this callback will be confused by this situation.
>> Given the fact that moderm sdhci variant hosts are very prone to get
>> the timeout clock from common clock framework (actually the only three
>> users did that), it's more natural to return the value in Hz and we
>> make an explicit comment there. Then we put the unit conversion inside
>> the sdhci core. Thus will improve the code and prevent further misuses.
>>
>> [1]: https://patchwork.kernel.org/patch/9569431/
>>
>> Cc: Adrian Hunter <adrian.hunter@intel.com>
>> Cc: Anssi Hannula <anssi.hannula@bitwise.fi>
>> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
>> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>
> Shawn, can you please re-base this as doesn't apply to my next branch.
>
> While doing that, I would recommend to not refer to a patchwork link
> in the changelog. It's better to do that in the section where you
> describe the version history.
>
> Instead I would add a "Reported-by: Anssi Hannula
> <anssi.hannula@bitwise.fi>", to give Anssi cred about reporting the
> issue.
Sure, I will do that. Thanks.
>
> Kind regards
> Uffe
>
>> ---
>>
>> Changes in v5:
>> - fix typo
>> - remove unlikely
>>
>> Changes in v4:
>> - rebased on -next
>> - add Masahiro's ack for sdhci-cadence
>>
>> Changes in v3:
>> - squash all the patches into one to keep bisectability
>> - fix wrong return value of sdhci-cadence
>> - slight improve the condition check to avoid the complaint of
>> checkpatch
>>
>> Changes in v2:
>> - fix the comment and make it return in Hz
>>
>> drivers/mmc/host/sdhci-cadence.c | 4 ++--
>> drivers/mmc/host/sdhci-of-arasan.c | 17 +----------------
>> drivers/mmc/host/sdhci.c | 16 +++++++++-------
>> drivers/mmc/host/sdhci.h | 1 +
>> 4 files changed, 13 insertions(+), 25 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
>> index 316cfec..7baeeaf 100644
>> --- a/drivers/mmc/host/sdhci-cadence.c
>> +++ b/drivers/mmc/host/sdhci-cadence.c
>> @@ -103,9 +103,9 @@ static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
>> {
>> /*
>> * Cadence's spec says the Timeout Clock Frequency is the same as the
>> - * Base Clock Frequency. Divide it by 1000 to return a value in kHz.
>> + * Base Clock Frequency.
>> */
>> - return host->max_clk / 1000;
>> + return host->max_clk;
>> }
>>
>> static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
>> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
>> index 1cfd7f9..c52f153 100644
>> --- a/drivers/mmc/host/sdhci-of-arasan.c
>> +++ b/drivers/mmc/host/sdhci-of-arasan.c
>> @@ -157,21 +157,6 @@ static int sdhci_arasan_syscon_write(struct sdhci_host *host,
>> return ret;
>> }
>>
>> -static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
>> -{
>> - unsigned long freq;
>> - struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> -
>> - /* SDHCI timeout clock is in kHz */
>> - freq = DIV_ROUND_UP(clk_get_rate(pltfm_host->clk), 1000);
>> -
>> - /* or in MHz */
>> - if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
>> - freq = DIV_ROUND_UP(freq, 1000);
>> -
>> - return freq;
>> -}
>> -
>> static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
>> {
>> struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> @@ -286,7 +271,7 @@ static int sdhci_arasan_voltage_switch(struct mmc_host *mmc,
>> static struct sdhci_ops sdhci_arasan_ops = {
>> .set_clock = sdhci_arasan_set_clock,
>> .get_max_clock = sdhci_pltfm_clk_get_max_clock,
>> - .get_timeout_clock = sdhci_arasan_get_timeout_clock,
>> + .get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
>> .set_bus_width = sdhci_set_bus_width,
>> .reset = sdhci_arasan_reset,
>> .set_uhs_signaling = sdhci_set_uhs_signaling,
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index 6fdd7a7..4a9df4ac 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -3289,20 +3289,22 @@ int sdhci_setup_host(struct sdhci_host *host)
>> if (!(host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)) {
>> host->timeout_clk = (host->caps & SDHCI_TIMEOUT_CLK_MASK) >>
>> SDHCI_TIMEOUT_CLK_SHIFT;
>> +
>> + if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
>> + host->timeout_clk *= 1000;
>> +
>> if (host->timeout_clk == 0) {
>> - if (host->ops->get_timeout_clock) {
>> - host->timeout_clk =
>> - host->ops->get_timeout_clock(host);
>> - } else {
>> + if (!host->ops->get_timeout_clock) {
>> pr_err("%s: Hardware doesn't specify timeout clock frequency.\n",
>> mmc_hostname(mmc));
>> ret = -ENODEV;
>> goto undma;
>> }
>> - }
>>
>> - if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
>> - host->timeout_clk *= 1000;
>> + host->timeout_clk =
>> + DIV_ROUND_UP(host->ops->get_timeout_clock(host),
>> + 1000);
>> + }
>>
>> if (override_timeout_clk)
>> host->timeout_clk = override_timeout_clk;
>> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
>> index edf3adf..27c252c 100644
>> --- a/drivers/mmc/host/sdhci.h
>> +++ b/drivers/mmc/host/sdhci.h
>> @@ -547,6 +547,7 @@ struct sdhci_ops {
>> int (*enable_dma)(struct sdhci_host *host);
>> unsigned int (*get_max_clock)(struct sdhci_host *host);
>> unsigned int (*get_min_clock)(struct sdhci_host *host);
>> + /* get_timeout_clock should return clk rate in unit of Hz */
>> unsigned int (*get_timeout_clock)(struct sdhci_host *host);
>> unsigned int (*get_max_timeout_count)(struct sdhci_host *host);
>> void (*set_timeout)(struct sdhci_host *host,
>> --
>> 1.9.1
>>
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2017-03-24 7:44 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2017-03-17 3:11 [PATCH v5] mmc: sdhci: clarify the get_timeout_clock callback Shawn Lin
2017-03-24 7:40 ` Ulf Hansson
2017-03-24 7:43 ` Shawn Lin
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