Re: [PATCH v2] mmc: sdhci-of-arasan: fix set_clock when a phy is supported

Shawn Lin
2016-05-04T09:25:05Z

在 2016/5/4 16:35, Heiko Stuebner 写道:
> Am Mittwoch, 4. Mai 2016, 09:48:55 schrieb Shawn Lin:
>> 在 2016/4/28 18:38, Ulf Hansson 写道:
>>> On 28 April 2016 at 10:38, Shawn Lin <shawn.lin@rock-chips.com> wrote:
>>>> commit 61b914eb81f8 ("mmc: sdhci-of-arasan: add phy support for
>>>> sdhci-of-arasan") introduce phy support for arasan. According to
>>>> the vendor's databook, we should make sure the phy is in poweroff
>>>> status before we configure the clk stuff. Otherwise it may cause
>>>> some IO sample timing issues from the test. And we don't need this
>>>> extra operation while running in low performance mode since phy
>>>> doesn't trigger sampling block.
>>>>
>>>> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
>>>
>>> Thanks, applied for next!
>>
>> Thanks for applying v2 but, could you please drop it and applied v3
>> I just send :) .
>> Because v2 introduces a bug. Set_clock callback will be
>> called under the protection of spinlock in sdhci_do_set_ios. However
>> PHY APIs need mutex which fails the kernel's debug check
>>
>> BUG: sleeping function called from invalid context at
>> kernel/locking/mutex.c
>
> I think in general you will need to provide a follow-up patch instead of
> replacing the old version, as Ulf might not want to restructure an already
> published branch (depends on the maintainer), especially as already other
> stuff is on top of your patch [0].
>

Aha.. yes I see other patches on top of mine now. Thanks for reminding
it.

Ulf, would you mind that I send a new patch to fix it, or you are prone
to restructure the next?

>
> Heiko
>
> [0]
> https://git.linaro.org/people/ulf.hansson/mmc.git/shortlog/refs/heads/next
>
>
>
>
>>> Kind regards
>>> Uffe
>>>
>>>> ---
>>>>
>>>> Changes in v2:
>>>> - change commit msg title to indicate it's a fix
>>>> - fix a typo in commmit msg
>>>>
>>>> drivers/mmc/host/sdhci-of-arasan.c | 20 +++++++++++++++++++-
>>>> 1 file changed, 19 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/mmc/host/sdhci-of-arasan.c
>>>> b/drivers/mmc/host/sdhci-of-arasan.c index 2e482b1..20b859e 100644
>>>> --- a/drivers/mmc/host/sdhci-of-arasan.c
>>>> +++ b/drivers/mmc/host/sdhci-of-arasan.c
>>>> @@ -55,8 +55,26 @@ static unsigned int
>>>> sdhci_arasan_get_timeout_clock(struct sdhci_host *host)>>
>>>> return freq;
>>>>
>>>> }
>>>>
>>>> +static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned
>>>> int clock) +{
>>>> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>>> + struct sdhci_arasan_data *sdhci_arasan =
>>>> sdhci_pltfm_priv(pltfm_host); + bool ctrl_phy = false;
>>>> +
>>>> + if (clock > MMC_HIGH_52_MAX_DTR &&
>>>> (!IS_ERR(sdhci_arasan->phy)))
>>>> + ctrl_phy = true;
>>>> +
>>>> + if (ctrl_phy)
>>>> + phy_power_off(sdhci_arasan->phy);
>>>> +
>>>> + sdhci_set_clock(host, clock);
>>>> +
>>>> + if (ctrl_phy)
>>>> + phy_power_on(sdhci_arasan->phy);
>>>> +}
>>>> +
>>>>
>>>> static struct sdhci_ops sdhci_arasan_ops = {
>>>>
>>>> - .set_clock = sdhci_set_clock,
>>>> + .set_clock = sdhci_arasan_set_clock,
>>>>
>>>> .get_max_clock = sdhci_pltfm_clk_get_max_clock,
>>>> .get_timeout_clock = sdhci_arasan_get_timeout_clock,
>>>> .set_bus_width = sdhci_set_bus_width,
>>>>
>>>> --
>>>> 2.3.7
>>>>
>>>>
>>>> --
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>
>
>
>

--
Best Regards
Shawn Lin