On 16.02.2023 15:53, Lars-Peter Clausen wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the > content is safe > > On 2/16/23 01:49, Claudiu.Beznea@xxxxxxxxxxxxx wrote: >> On 14.02.2023 23:26, Mark Brown wrote: >>> On Tue, Feb 14, 2023 at 10:14:28AM -0800, Lars-Peter Clausen wrote: >>>> On 2/14/23 08:14, Claudiu Beznea wrote: >>>>> @@ -450,6 +450,8 @@ int snd_dmaengine_pcm_register(struct device *dev, >>>>> else >>>>> driver = &dmaengine_pcm_component; >>>>> + driver->start_dma_last = config->start_dma_last; >>>> This will break if you have multiple sound cards in the system. >>>> dmaengine_pcm_component must stay const. >>> Right, if we need to modify it we either need to select which of >>> multiple const structs to register or to take a copy and modify >>> that. I've not looked at the actual changes yet. >> OK, I will try that and return with a new patch. >> >> On the other hand do you think the other solution presented in cover letter >> would be better? From the cover letter: >> >> "The other solution that was identified for this was to extend the already >> existing mechanism around struct snd_soc_dai_link::stop_dma_first. The >> downside >> of this was that a potential struct snd_soc_dai_link::start_dma_last >> would have to be populated on sound card driver thus, had to be taken >> into account in all sound card drivers. At the moment, the mchp-pdmc is >> used only with simple-audio-card. In case of simple-audio-card a new DT >> binding would had to be introduced to specify this action on dai-link >> descriptions (as of my investigation)." >> > Can't you just set `start_dma_last` on the `mchp_pdmc_dai_component`? In > your code you iterate over all the components of the link and if any of > them has it set the DMA is started last. Yes, that is also working. In this patch I chose to have it on DMA component as the operation is specific to DMA... It looked better to me this way. But is true that having it on mchp_pdmc_dai_component wouldn't affect the behavior. Thank you, Claudiu
