Re: [PATCH 3/4] ASoC: ti: davinci-mcasp: Streamline pdir behavior across rx & tx streams

[Sen Wang <sen@ti.com>]

On 2/2/26 10:49, Péter Ujfalusi wrote:
> 
> 
> On 30/01/2026 07:10, Sen Wang wrote:
>> Simplify the mcasp_set_clk_pdir caller convention in start/stop stream
>> function, to make it so that set_clk_pdir gets called regardless when
>> stream starts and also disables when stream ends.
>>
>> Functionality-wise, everything remains the same as the previously skipped
>> calls are now either correctly configured
>> (when McASP is SND_SOC_DAIFMT_BP_FC - pdir needs to be enabled)
>> or called with a bitmask of zero (when McASP is SND_SOC_DAIFMT_BC_FC - pdir
>> gets disabled).
>>
>> On brief regarding McASP Clock and Frame sync configurations, refer to [0].
>>
>> [0]:TRM Section 12.1.1.4.2 https://www.ti.com/lit/ug/sprujd4a/sprujd4a.pdf
>>
>> Signed-off-by: Sen Wang <sen@ti.com>
>> ---
>>   sound/soc/ti/davinci-mcasp.c | 10 +++++-----
>>   1 file changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/sound/soc/ti/davinci-mcasp.c b/sound/soc/ti/davinci-mcasp.c
>> index aa14fc1c8011..4f8a2ce6ce78 100644
>> --- a/sound/soc/ti/davinci-mcasp.c
>> +++ b/sound/soc/ti/davinci-mcasp.c
>> @@ -235,8 +235,8 @@ static void mcasp_start_rx(struct davinci_mcasp *mcasp)
>>   	if (mcasp_is_frame_producer(mcasp) && mcasp_is_synchronous(mcasp)) {
>>   		mcasp_set_ctl_reg(mcasp, DAVINCI_MCASP_GBLCTLX_REG, TXHCLKRST);
>>   		mcasp_set_ctl_reg(mcasp, DAVINCI_MCASP_GBLCTLX_REG, TXCLKRST);
>> -		mcasp_set_clk_pdir(mcasp, true);
>>   	}
>> +	mcasp_set_clk_pdir(mcasp, true);
>>   
>>   	/* Activate serializer(s) */
>>   	mcasp_set_reg(mcasp, DAVINCI_MCASP_RXSTAT_REG, 0xFFFFFFFF);
>> @@ -311,10 +311,10 @@ static void mcasp_stop_rx(struct davinci_mcasp *mcasp)
>>   	 * In synchronous mode stop the TX clocks if no other stream is
>>   	 * running
>>   	 */
>> -	if (mcasp_is_frame_producer(mcasp) && mcasp_is_synchronous(mcasp) && !mcasp->streams) {
>> -		mcasp_set_clk_pdir(mcasp, false);
>> +	if (mcasp_is_frame_producer(mcasp) && mcasp_is_synchronous(mcasp) && !mcasp->streams)
>>   		mcasp_set_reg(mcasp, DAVINCI_MCASP_GBLCTLX_REG, 0);
>> -	}
>> +	if (!mcasp->streams)
>> +		mcasp_set_clk_pdir(mcasp, false);
> 
> I'm not sure about this, but the sequence should be preserved, PDIR
> change first.
> 

Sounds good, I'll enforce the original order of operation in the new patch.

>>   
>>   	mcasp_set_reg(mcasp, DAVINCI_MCASP_GBLCTLR_REG, 0);
>>   	mcasp_set_reg(mcasp, DAVINCI_MCASP_RXSTAT_REG, 0xFFFFFFFF);
>> @@ -340,7 +340,7 @@ static void mcasp_stop_tx(struct davinci_mcasp *mcasp)
>>   	 */
>>   	if (mcasp_is_frame_producer(mcasp) && mcasp_is_synchronous(mcasp) && mcasp->streams)
>>   		val =  TXHCLKRST | TXCLKRST | TXFSRST;
>> -	else
>> +	if (!mcasp->streams)
>>   		mcasp_set_clk_pdir(mcasp, false);
>>   
>>   
> 

Best,
Sen Wang