Re: [PATCH v2 1/2] sdhci: tegra: Implement Tegra specific set_timeout callback

[Sowjanya Komatineni <skomatineni@nvidia.com>]

On 4/16/20 9:29 AM, Sowjanya Komatineni wrote:
>
> On 4/16/20 3:59 AM, Ulf Hansson wrote:
>> External email: Use caution opening links or attachments
>>
>>
>> On Wed, 15 Apr 2020 at 19:55, Naresh Kamboju 
>> <naresh.kamboju@linaro.org> wrote:
>>> On Fri, 13 Mar 2020 at 06:41, Sowjanya Komatineni
>>> <skomatineni@nvidia.com> wrote:
>>>> Tegra host supports HW busy detection and timeouts based on the
>>>> count programmed in SDHCI_TIMEOUT_CONTROL register and max busy
>>>> timeout it supports is 11s in finite busy wait mode.
>>>>
>>>> Some operations like SLEEP_AWAKE, ERASE and flush cache through
>>>> SWITCH commands take longer than 11s and Tegra host supports
>>>> infinite HW busy wait mode where HW waits forever till the card
>>>> is busy without HW timeout.
>>>>
>>>> This patch implements Tegra specific set_timeout sdhci_ops to allow
>>>> switching between finite and infinite HW busy detection wait modes
>>>> based on the device command expected operation time.
>>>>
>>>> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
>>>> ---
>>>>   drivers/mmc/host/sdhci-tegra.c | 31 +++++++++++++++++++++++++++++++
>>>>   1 file changed, 31 insertions(+)
>>>>
>>>> diff --git a/drivers/mmc/host/sdhci-tegra.c 
>>>> b/drivers/mmc/host/sdhci-tegra.c
>>>> index a25c3a4..fa8f6a4 100644
>>>> --- a/drivers/mmc/host/sdhci-tegra.c
>>>> +++ b/drivers/mmc/host/sdhci-tegra.c
>>>> @@ -45,6 +45,7 @@
>>>>   #define SDHCI_TEGRA_CAP_OVERRIDES_DQS_TRIM_SHIFT       8
>>>>
>>>>   #define SDHCI_TEGRA_VENDOR_MISC_CTRL 0x120
>>>> +#define SDHCI_MISC_CTRL_ERASE_TIMEOUT_LIMIT BIT(0)
>>>>   #define SDHCI_MISC_CTRL_ENABLE_SDR104                  0x8
>>>>   #define SDHCI_MISC_CTRL_ENABLE_SDR50 0x10
>>>>   #define SDHCI_MISC_CTRL_ENABLE_SDHCI_SPEC_300 0x20
>>>> @@ -1227,6 +1228,34 @@ static u32 sdhci_tegra_cqhci_irq(struct 
>>>> sdhci_host *host, u32 intmask)
>>>>          return 0;
>>>>   }
>>>>
>>>> +static void tegra_sdhci_set_timeout(struct sdhci_host *host,
>>>> +                                   struct mmc_command *cmd)
>>>> +{
>>>> +       u32 val;
>>>> +
>>>> +       /*
>>>> +        * HW busy detection timeout is based on programmed data 
>>>> timeout
>>>> +        * counter and maximum supported timeout is 11s which may 
>>>> not be
>>>> +        * enough for long operations like cache flush, sleep 
>>>> awake, erase.
>>>> +        *
>>>> +        * ERASE_TIMEOUT_LIMIT bit of VENDOR_MISC_CTRL register allows
>>>> +        * host controller to wait for busy state until the card is 
>>>> busy
>>>> +        * without HW timeout.
>>>> +        *
>>>> +        * So, use infinite busy wait mode for operations that may 
>>>> take
>>>> +        * more than maximum HW busy timeout of 11s otherwise use 
>>>> finite
>>>> +        * busy wait mode.
>>>> +        */
>>>> +       val = sdhci_readl(host, SDHCI_TEGRA_VENDOR_MISC_CTRL);
>>>> +       if (cmd && cmd->busy_timeout >= 11 * HZ)
>>>> +               val |= SDHCI_MISC_CTRL_ERASE_TIMEOUT_LIMIT;
>>>> +       else
>>>> +               val &= ~SDHCI_MISC_CTRL_ERASE_TIMEOUT_LIMIT;
>>>> +       sdhci_writel(host, val, SDHCI_TEGRA_VENDOR_MISC_CTRL);
>>>> +
>>>> +       __sdhci_set_timeout(host, cmd);
>>> kernel build on arm and arm64 architecture failed on stable-rc 4.19
>>> (arm), 5.4 (arm64) and 5.5 (arm64)
>>>
>>> drivers/mmc/host/sdhci-tegra.c: In function 'tegra_sdhci_set_timeout':
>>> drivers/mmc/host/sdhci-tegra.c:1256:2: error: implicit declaration of
>>> function '__sdhci_set_timeout'; did you mean
>>> 'tegra_sdhci_set_timeout'? [-Werror=implicit-function-declaration]
>>>    __sdhci_set_timeout(host, cmd);
>>>    ^~~~~~~~~~~~~~~~~~~
>>>    tegra_sdhci_set_timeout
>>>
>>> Full build log,
>>> https://ci.linaro.org/view/lkft/job/openembedded-lkft-linux-stable-rc-5.5/DISTRO=lkft,MACHINE=am57xx-evm,label=docker-lkft/83/consoleText 
>>>
>>> https://ci.linaro.org/view/lkft/job/openembedded-lkft-linux-stable-rc-5.4/DISTRO=lkft,MACHINE=juno,label=docker-lkft/158/consoleText 
>>>
>>> https://ci.linaro.org/view/lkft/job/openembedded-lkft-linux-stable-rc-4.19/DISTRO=lkft,MACHINE=am57xx-evm,label=docker-lkft/511/consoleText 
>>>
>>>
>>> - Naresh
>> Thanks for reporting! What a mess.
>>
>> It turns out that the commit that was queued for stable that is
>> causing the above errors, also requires another commit.
>>
>> The commit that was queued:
>> 5e958e4aacf4 ("sdhci: tegra: Implement Tegra specific set_timeout 
>> callback")
>>
>> The additional commit needed (which was added in v5.6-rc1):
>> 7d76ed77cfbd ("mmc: sdhci: Refactor sdhci_set_timeout()")
>>
>> However, the above commit needs a manual backport (quite trivial, but
>> still) for the relevant stable kernels, to allow it to solve the build
>> problems.
>>
>> Greg, Sasha - I suggest you to drop the offending commit from the
>> stable kernels, for now. I think it's better to let Sowjanya deal with
>> the backports, then send them in small series instead.
>>
>> Kind regards
>> Uffe
>
> Hi Ufee,
>
> Will back-porting below commit cause any issues to other vendors?
>
> 7d76ed77cfbd ("mmc: sdhci: Refactor sdhci_set_timeout()")
>
sdhci-tegra driver in 4.19 is using same sdhci_ops for Tegra114 and 
Tegra210 and separate sdhci_ops for T210 started from 4.20.

5e958e4aacf4 ("sdhci: tegra: Implement Tegra specific set_timeout callback")

So above commit can't be applied to 4.19. So probably a separate patch 
need to be created to apply for 4.19 and back port above commit along 
with its dependency commit (7d76ed77cfbd ("mmc: sdhci: Refactor 
sdhci_set_timeout()") for 5.4 and 5.4.


> Thanks
Sowjanya
>