Re: [PATCH] mmc: sdhci-msm: pervent access to suspended controller

[Adrian Hunter]

On 27/03/24 17:17, Ulf Hansson wrote:
> On Tue, 26 Mar 2024 at 11:25, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
>>
>> On 21/03/24 16:30, Mantas Pucka wrote:
>>> Generic sdhci code registers LED device and uses host->runtime_suspended
>>> flag to protect access to it. The sdhci-msm driver doesn't set this flag,
>>> which causes a crash when LED is accessed while controller is runtime
>>> suspended. Fix this by setting the flag correctly.
>>>
>>> Cc: stable@xxxxxxxxxxxxxxx
>>> Fixes: 67e6db113c90 ("mmc: sdhci-msm: Add pm_runtime and system PM support")
>>> Signed-off-by: Mantas Pucka <mantas@xxxxxxxxxxxx>
>>
>> Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> 
> Looks like this problem may exist for other sdhci drivers too. In
> particular for those that enables runtime PM, don't set
> SDHCI_QUIRK_NO_LED and don't use sdhci_runtime|suspend_resume_host().
> 
> Don't know if there is a better way to address this, if not on a case
> by case basis. Do you have any thoughts about this?

Yes probably case by case, but I will look at it.

> 
> Kind regards
> Uffe
> 
>>
>>> ---
>>>  drivers/mmc/host/sdhci-msm.c | 16 +++++++++++++++-
>>>  1 file changed, 15 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
>>> index 668e0aceeeba..e113b99a3eab 100644
>>> --- a/drivers/mmc/host/sdhci-msm.c
>>> +++ b/drivers/mmc/host/sdhci-msm.c
>>> @@ -2694,6 +2694,11 @@ static __maybe_unused int sdhci_msm_runtime_suspend(struct device *dev)
>>>       struct sdhci_host *host = dev_get_drvdata(dev);
>>>       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>>       struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
>>> +     unsigned long flags;
>>> +
>>> +     spin_lock_irqsave(&host->lock, flags);
>>> +     host->runtime_suspended = true;
>>> +     spin_unlock_irqrestore(&host->lock, flags);
>>>
>>>       /* Drop the performance vote */
>>>       dev_pm_opp_set_rate(dev, 0);
>>> @@ -2708,6 +2713,7 @@ static __maybe_unused int sdhci_msm_runtime_resume(struct device *dev)
>>>       struct sdhci_host *host = dev_get_drvdata(dev);
>>>       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>>       struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
>>> +     unsigned long flags;
>>>       int ret;
>>>
>>>       ret = clk_bulk_prepare_enable(ARRAY_SIZE(msm_host->bulk_clks),
>>> @@ -2726,7 +2732,15 @@ static __maybe_unused int sdhci_msm_runtime_resume(struct device *dev)
>>>
>>>       dev_pm_opp_set_rate(dev, msm_host->clk_rate);
>>>
>>> -     return sdhci_msm_ice_resume(msm_host);
>>> +     ret = sdhci_msm_ice_resume(msm_host);
>>> +     if (ret)
>>> +             return ret;
>>> +
>>> +     spin_lock_irqsave(&host->lock, flags);
>>> +     host->runtime_suspended = false;
>>> +     spin_unlock_irqrestore(&host->lock, flags);
>>> +
>>> +     return ret;
>>>  }
>>>
>>>  static const struct dev_pm_ops sdhci_msm_pm_ops = {
>>>
>>> ---
>>> base-commit: e8f897f4afef0031fe618a8e94127a0934896aba
>>> change-id: 20240321-sdhci-mmc-suspend-34f4af1d0286
>>>
>>> Best regards,
>>