[PATCH 0/2] r8152: Fix a couple of PM problems
From: Takashi Iwai <hidden>
Date: 2021-07-14 17:00:31
Hi, it seems that r8152 driver suffers from the deadlock at both runtime and system PM. Formerly, it was seen more often at hibernation resume, but now it's triggered more frequently, as reported in SUSE Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1186194 While debugging the problem, I stumbled on a few obvious bugs and here is the results with two patches for addressing the resume problem. *** However, the story doesn't end here, unfortunately, and those patches don't seem sufficing. The rest major problem is that the driver calls napi_disable() and napi_enable() in the PM suspend callbacks. This makes the system stalling at (runtime-)suspend. If we drop napi_disable() and napi_enable() calls in the PM suspend callbacks, it starts working (that was the result in Bugzilla comment 13): https://bugzilla.suse.com/show_bug.cgi?id=1186194#c13 So, my patches aren't enough and we still need to investigate further. It'd be appreciated if anyone can give a fix or a hint for more debugging. The usage of napi_disable() at PM callbacks is unique in this driver and looks rather suspicious to me; but I'm no expert in this area so I might be wrong... Thanks! Takashi === Takashi Iwai (2): r8152: Fix potential PM refcount imbalance r8152: Fix a deadlock by doubly PM resume drivers/net/usb/r8152.c | 30 ++++++++++++++++++++---------- 1 file changed, 20 insertions(+), 10 deletions(-) -- 2.26.2