On Tue, May 19, 2020 at 3:32 AM Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> wrote: > > Hi > > On 19.05.2020 09:11, Marek Szyprowski wrote: > > On 19.05.2020 08:48, Saravana Kannan wrote: > >> On Mon, May 18, 2020 at 11:25 PM Marek Szyprowski > >> <m.szyprowski@xxxxxxxxxxx> wrote: > >>> On 15.05.2020 07:35, Saravana Kannan wrote: > >>>> The fw_devlink_pause() and fw_devlink_resume() APIs allow batching the > >>>> parsing of the device tree nodes when a lot of devices are added. This > >>>> will significantly cut down parsing time (as much a 1 second on some > >>>> systems). So, use them when adding devices for all the top level > >>>> device > >>>> tree nodes in a system. > >>>> > >>>> Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx> > >>> This patch recently landed in linux-next 20200518. Sadly, it causes > >>> regression on Samsung Exynos5433-based TM2e board: > >>> > >>> ... > >>> > >>> Both issues, the lack of DMA for SPI device and Synchronous abort in > >>> I2S > >>> probe are new after applying this patch. I'm trying to investigate > >>> which > >>> resources are missing and why. The latter issue means typically that > >>> the > >>> registers for the given device has been accessed without enabling the > >>> needed clocks or power domains. > >> Did you try this copy-pasta fix that I sent later? > >> https://lore.kernel.org/lkml/20200517173453.157703-1-saravanak@xxxxxxxxxx/ > >> > >> > >> Not every system would need it (my test setup didn't), but it helps > >> some cases. > >> > >> If that fix doesn't help, then some tips for debugging the failing > >> drivers. > >> What this pause/resume patch effectively (not explicitly) does is: > >> 1. Doesn't immediately probe the devices as they are added in > >> of_platform_default_populate_init() > >> 2. Adds them in order to the deferred probe list. > >> 3. Then kicks off deferred probe on them in the order they were added. > >> > >> These drivers are just not handling -EPROBE_DEFER correctly or > >> assuming probe order and that's causing these issues. > >> > >> So, we can either fix that or you can try adding some code to flush > >> the deferred probe workqueue at the end of fw_devlink_resume(). > >> > >> Let me know how it goes. > > > > So far it looks that your patch revealed a hidden issue in exynos5433 > > clocks configuration, because adding clk_ignore_unused parameter to > > kernel command line fixes the boot. I'm still investigating it, so > > probable you can ignore my regression report. I will let you know asap > > I finish checking it. > > > Okay, I confirm that the issue is in the Exynos I2S driver and > Exynos5433 clock provider. I've posted a quick workaround. I'm sorry for > the noise, your patch is fine. Thanks for debugging and finding the real issue. I tried finding your patches, but couldn't. Can you point me to a lore.kernel.org link? I'm just curious to see what the issue was. I'm guessing you didn't need to pick up this one? https://lore.kernel.org/lkml/20200517173453.157703-1-saravanak@xxxxxxxxxx/ -Saravana
