From mboxrd@z Thu Jan 1 00:00:00 1970 From: grygorii.strashko@ti.com (Grygorii Strashko) Date: Tue, 25 Jul 2017 12:41:27 -0500 Subject: [PATCH] ARM: OMAP2+: omap_device: drop broken RPM status update from suspend_noirq In-Reply-To: <20170725085617.GR10026@atomide.com> References: <20170724095201.21601-1-johan@kernel.org> <05ae4585-8da0-6fb1-8cfd-6b236ec3a8a2@ti.com> <20170725071048.GP10026@atomide.com> <20170725085617.GR10026@atomide.com> Message-ID: <9b846eee-4e44-6909-60d8-99ee86e6a212@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 07/25/2017 03:56 AM, Tony Lindgren wrote: > * Tony Lindgren [170725 00:11]: >> * Grygorii Strashko [170724 15:17]: >>> My personal thought here is that removing of pm_runtime_set_active() will not fix >>> root cause of the problem, but rather hide it :( and, probably, real fix will be >>> to update USB framework to ensure that all suspend devices are also PM runtime suspend >>> (not sure how) or add few more pm_suspend_ignore_children() calls >>> (for example as I've tried to do in [2], but this was unfinished). >>> >>> I've found very simple steps to reproduce suspend failure on am335x-evm (should also >>> work on BBB) - do below sequence with USB device plugged: >>> >>> echo platform > /sys/power/pm_test >>> echo 1 > /sys/power/pm_print_times >>> [ echo 0 > /sys/module/printk/parameters/console_suspend ] >>> echo mem > /sys/power/state >>> >>> [ 95.499685] calling 47400000.usb+ @ 733, parent: ocp >>> [ 95.504818] am335x-usb-childs 47400000.usb: runtime PM trying to suspend device but active child >>> [ 95.513750] am335x-usb-childs 47400000.usb: omap device suspend failure 0 >>> >>> Below I've attached possible patch which converts OMAP device to >>> use pm_runtime_force_suspend/resume(). >> >> It seems to almost work for my PM test cases.. It seems that serial console >> somehow won't get restored after suspend/resume cycle on omap3 though. >> >> The system enters off mode during suspend, and wakes up properly so I can >> ssh to it after resume. But the serial console no longer works after resume. >> This is with 8250-omap driver. > > And FYI, on omap4 this produces a bunch of L3 irq errors on suspend. > Ok. This was a risky change even if it looks obvious :( -- regards, -grygorii