On Thu, Jan 02, 2020 at 06:09:45PM +0300, Dmitry Osipenko wrote: > 30.12.2019 23:50, Michał Mirosław пишет: > > On Mon, Dec 30, 2019 at 09:45:55PM +0100, Michał Mirosław wrote: > >> On Sat, Dec 28, 2019 at 11:46:36PM +0300, Dmitry Osipenko wrote: > >>> It's unsafe to check the channel's "busy" state without taking a lock, > >>> it is also unsafe to assume that tasklet isn't in-fly. > >> > >> 'in-flight'. Also, the patch seems to have two independent bug-fixes > >> in it. Second one doesn't look right, at least not without an explanation. > >> > >> First: > >> > >>> - if (tdc->busy) > >>> - tegra_dma_terminate_all(dc); > >>> + tegra_dma_terminate_all(dc); > >> > >> Second: > >> > >>> + tasklet_kill(&tdc->tasklet); > > > > BTW, maybe you can convert the code to threaded interrupt handler and > > just get rid of the tasklet instead of fixing it? > > This shouldn't bring much benefit because the the code's logic won't be > changed since we will still have to use the threaded ISR part as the > bottom-half and then IRQ API doesn't provide a nice way to synchronize > interrupt's execution, while tasklet_kill() is a nice way to sync it. What about synchronize_irq()? BTW, does tegra_dma_terminate_all() prevent further interrupts that might cause the tasklet to be scheduled again? Best Regards, Michał Mirosław
