linux-kernel - Re: [alsa-devel] [RFC PATCH 23/40] soundwire: stream: fix disable sequence

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Message-ID: <8ec39464-81f7-e29d-7a2c-b2903a7fbf60@linux.intel.com>
Date:   Fri, 26 Jul 2019 10:05:54 -0500
From:   Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>
To:     Guennadi Liakhovetski <guennadi.liakhovetski@...ux.intel.com>
Cc:     alsa-devel@...a-project.org, tiwai@...e.de,
        gregkh@...uxfoundation.org, linux-kernel@...r.kernel.org,
        vkoul@...nel.org, broonie@...nel.org,
        srinivas.kandagatla@...aro.org, jank@...ence.com,
        slawomir.blauciak@...el.com, Sanyog Kale <sanyog.r.kale@...el.com>
Subject: Re: [alsa-devel] [RFC PATCH 23/40] soundwire: stream: fix disable
 sequence


> Unrelated to this specific patch, but I looked at _sdw_disable_stream()
> and I see this there (again, maybe my version is outdated already):
> 
> 	struct sdw_master_runtime *m_rt = NULL;
> 	struct sdw_bus *bus = NULL;
> 
> where both those initialisations are redundant. Moreover:

will look at this, thanks.

> 
> On Thu, Jul 25, 2019 at 06:40:15PM -0500, Pierre-Louis Bossart wrote:
>> When we disable the stream and then call hw_free, two bank switches
>> will be handled and as a result we re-enable the stream on hw_free.
>>
>> Make sure the stream is disabled on both banks.
>>
>> TODO: we need to completely revisit all this and make sure we have a
>> mirroring mechanism between current and alternate banks.
>>
>> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>
>> ---
>>   drivers/soundwire/stream.c | 19 ++++++++++++++++++-
>>   1 file changed, 18 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c
>> index 53f5e790fcd7..75b9ad1fb1a6 100644
>> --- a/drivers/soundwire/stream.c
>> +++ b/drivers/soundwire/stream.c
>> @@ -1637,7 +1637,24 @@ static int _sdw_disable_stream(struct sdw_stream_runtime *stream)
>>   		}
>>   	}
>>   
>> -	return do_bank_switch(stream);
>> +	ret = do_bank_switch(stream);
>> +	if (ret < 0) {
>> +		dev_err(bus->dev, "Bank switch failed: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	/* make sure alternate bank (previous current) is also disabled */
>> +	list_for_each_entry(m_rt, &stream->master_list, stream_node) {
>> +		bus = m_rt->bus;
> 
> "bus" is only used below, so at least take that line under "if (ret < 0)"
> or even just do "dev_err(m_rt->bus->dev,...)" everywhere in this function
> and remove the variable altogether...

will look at this, thanks Guennadi

> 
> Thanks
> Guennadi
> 
>> +		/* Disable port(s) */
>> +		ret = sdw_enable_disable_ports(m_rt, false);
>> +		if (ret < 0) {
>> +			dev_err(bus->dev, "Disable port(s) failed: %d\n", ret);
>> +			return ret;