Re: [alsa-devel] [RFC PATCH 17/40] soundwire: bus: use runtime_pm_get_sync/pm when enabled

Jan Kotas
2019-07-26T07:47:28Z

Hello,

I while back I proposed a patch for this, but it went nowhere.

https://patchwork.kernel.org/patch/10887405/
Maybe something similar can be implemented?

Jan

> On 26 Jul 2019, at 09:39, Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com> wrote:
>
> EXTERNAL MAIL
>
>
> Hi Pierre,
>
> I might be wrong but this doesn't seem right to me. (Supposedly) all RT-PM
> functions check for "enabled" internally. The only thing that can happen is
> that if RT-PM isn't enabled some of those functions will return an error.
> So, in those cases where the return value of RT-PM functions isn't checked,
> I don't think you need to do anything. Where it is checked maybe do
>
> + if (ret < 0 && pm_runtime_enabled(slave->bus->dev))
>
> Thanks
> Guennadi
>
> On Thu, Jul 25, 2019 at 06:40:09PM -0500, Pierre-Louis Bossart wrote:
>> Not all platforms support runtime_pm for now, let's use runtime_pm
>> only when enabled.
>>
>> Suggested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
>> ---
>> drivers/soundwire/bus.c | 25 ++++++++++++++++---------
>> 1 file changed, 16 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
>> index 5ad4109dc72f..0a45dc5713df 100644
>> --- a/drivers/soundwire/bus.c
>> +++ b/drivers/soundwire/bus.c
>> @@ -332,12 +332,16 @@ int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
>> if (ret < 0)
>> return ret;
>>
>> - ret = pm_runtime_get_sync(slave->bus->dev);
>> - if (ret < 0)
>> - return ret;
>> + if (pm_runtime_enabled(slave->bus->dev)) {
>> + ret = pm_runtime_get_sync(slave->bus->dev);
>> + if (ret < 0)
>> + return ret;
>> + }
>>
>> ret = sdw_transfer(slave->bus, &msg);
>> - pm_runtime_put(slave->bus->dev);
>> +
>> + if (pm_runtime_enabled(slave->bus->dev))
>> + pm_runtime_put(slave->bus->dev);
>>
>> return ret;
>> }
>> @@ -359,13 +363,16 @@ int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
>> slave->dev_num, SDW_MSG_FLAG_WRITE, val);
>> if (ret < 0)
>> return ret;
>> -
>> - ret = pm_runtime_get_sync(slave->bus->dev);
>> - if (ret < 0)
>> - return ret;
>> + if (pm_runtime_enabled(slave->bus->dev)) {
>> + ret = pm_runtime_get_sync(slave->bus->dev);
>> + if (ret < 0)
>> + return ret;
>> + }
>>
>> ret = sdw_transfer(slave->bus, &msg);
>> - pm_runtime_put(slave->bus->dev);
>> +
>> + if (pm_runtime_enabled(slave->bus->dev))
>> + pm_runtime_put(slave->bus->dev);
>>
>> return ret;
>> }
>> --
>> 2.20.1
>>
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