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. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
