2015-06-18 07:27:36

by Suneel Garapati

Subject: [PATCH] drivers: mmc: sdhci: update max frequency only if undefined

f_max parameter of mmc structure is updated unconditionally.
If dt property max-frequency is assigned, this update is
overwriting the dt property value which is undesired.

Signed-off-by: Suneel Garapati <[email protected]>
---
drivers/mmc/host/sdhci.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index bc14452..c2917d5 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3047,7 +3047,10 @@ int sdhci_add_host(struct sdhci_host *host)
* Set host parameters.
*/
mmc->ops = &sdhci_ops;
- mmc->f_max = host->max_clk;
+
+ if(!mmc->f_max)
+ mmc->f_max = host->max_clk;
+
if (host->ops->get_min_clock)
mmc->f_min = host->ops->get_min_clock(host);
else if (host->version >= SDHCI_SPEC_300) {
--
2.1.2

2015-06-18 07:33:56

by Dong Aisheng

Subject: Re: [PATCH] drivers: mmc: sdhci: update max frequency only if undefined

On Thu, Jun 18, 2015 at 12:57:07PM +0530, Suneel Garapati wrote:
> f_max parameter of mmc structure is updated unconditionally.
> If dt property max-frequency is assigned, this update is
> overwriting the dt property value which is undesired.
>
> Signed-off-by: Suneel Garapati <[email protected]>
> ---
> drivers/mmc/host/sdhci.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index bc14452..c2917d5 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -3047,7 +3047,10 @@ int sdhci_add_host(struct sdhci_host *host)
> * Set host parameters.
> */
> mmc->ops = &sdhci_ops;
> - mmc->f_max = host->max_clk;
> +
> + if(!mmc->f_max)
> + mmc->f_max = host->max_clk;
> +

This is probably not going to work properly.
mmc->f_max will be overwritten again if host->clk_mul enabled.
And you did not do sanity check if f_max from device tree is valid.

Please see:
http://www.spinics.net/lists/arm-kernel/msg426167.html
I already sent a proper fix.

Regards
Dong Aisheng

> if (host->ops->get_min_clock)
> mmc->f_min = host->ops->get_min_clock(host);
> else if (host->version >= SDHCI_SPEC_300) {
> --
> 2.1.2

2015-06-18 07:59:07

by Suneel G

Subject: Re: [PATCH] drivers: mmc: sdhci: update max frequency only if undefined

Hi,

On Thu, Jun 18, 2015 at 12:59 PM, Dong Aisheng <[email protected]> wrote:
> On Thu, Jun 18, 2015 at 12:57:07PM +0530, Suneel Garapati wrote:
>> f_max parameter of mmc structure is updated unconditionally.
>> If dt property max-frequency is assigned, this update is
>> overwriting the dt property value which is undesired.
>>
>> Signed-off-by: Suneel Garapati <[email protected]>
>> ---
>> drivers/mmc/host/sdhci.c | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index bc14452..c2917d5 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -3047,7 +3047,10 @@ int sdhci_add_host(struct sdhci_host *host)
>> * Set host parameters.
>> */
>> mmc->ops = &sdhci_ops;
>> - mmc->f_max = host->max_clk;
>> +
>> + if(!mmc->f_max)
>> + mmc->f_max = host->max_clk;
>> +
>
> This is probably not going to work properly.
> mmc->f_max will be overwritten again if host->clk_mul enabled.
> And you did not do sanity check if f_max from device tree is valid.
>
> Please see:
> http://www.spinics.net/lists/arm-kernel/msg426167.html
> I already sent a proper fix.

Ok, I missed your series.
My platform doesn't have clk_mul enabled hence couldn't check on that.
Agree on the sanity check.

Regards,
Suneel

>
> Regards
> Dong Aisheng
>
>> if (host->ops->get_min_clock)
>> mmc->f_min = host->ops->get_min_clock(host);
>> else if (host->version >= SDHCI_SPEC_300) {
>> --
>> 2.1.2
> --
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