Hi Tomi, On 03/20/2015 02:20 PM, Tomi Valkeinen wrote: > On 25/02/15 19:03, grygorii.strashko@xxxxxxxxxx wrote: >> From: Grygorii Strashko <Grygorii.Strashko@xxxxxxxxxx> >> >> Add handling of missed events in omap_dss_pm_notif which are >> needed to support hibernation (suspend to disk). >> >> Signed-off-by: Grygorii Strashko <Grygorii.Strashko@xxxxxxxxxx> >> --- >> drivers/video/fbdev/omap2/dss/core.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/drivers/video/fbdev/omap2/dss/core.c b/drivers/video/fbdev/omap2/dss/core.c >> index 6b74f73..e60976a 100644 >> --- a/drivers/video/fbdev/omap2/dss/core.c >> +++ b/drivers/video/fbdev/omap2/dss/core.c >> @@ -178,11 +178,15 @@ static int omap_dss_pm_notif(struct notifier_block *b, unsigned long v, void *d) >> DSSDBG("pm notif %lu\n", v); >> >> switch (v) { >> + case PM_HIBERNATION_PREPARE: >> case PM_SUSPEND_PREPARE: >> + case PM_RESTORE_PREPARE: >> DSSDBG("suspending displays\n"); >> return dss_suspend_all_devices(); >> >> case PM_POST_SUSPEND: >> + case PM_POST_HIBERNATION: >> + case PM_POST_RESTORE: >> DSSDBG("resuming displays\n"); >> return dss_resume_all_devices(); >> > > Why suspend displays when PM_RESTORE_PREPARE happens? Why resume when > PM_POST_RESTORE happens? We have following sequence when system is restored from hibernation: - original kernel booted; - late_initcall_sync(software_resume); - pm_notifier_call_chain(PM_RESTORE_PREPARE); - freeze_processes - check & read hibernation image - suspend all devices (.freeze()) - jump to stored kernel - restore devices ... So, all devices should be in frozen/suspended state when we will jump to stored kernel (device's state should be the same as before creating hib image). Without this patch I can see a lot of log messages like below: [ 3.642499] Freezing user space processes ... [ 3.647029] mmcblk1boot1: unknown partition table [ 3.647043] (elapsed 0.000 seconds) done. [ 3.686414] mmcblk1boot0: unknown partition table [ 3.714552] PM: Using 1 thread(s) for decompression. [ 3.714552] PM: Loading and decompressing image data (144641 pages)... [ 4.520388] PM: Image loading progress: 0% [ 5.153715] PM: Image loading progress: 10% [ 5.847731] PM: Image loading progress: 20% [ 6.622024] PM: Image loading progress: 30% [ 7.023830] PM: Image loading progress: 40% [ 7.455959] PM: Image loading progress: 50% [ 8.137186] PM: Image loading progress: 60% [ 8.567899] PM: Image loading progress: 70% [ 9.670371] PM: Image loading progress: 80% [ 10.130646] PM: Image loading progress: 90% [ 10.525035] PM: Image loading progress: 100% [ 10.529565] PM: Image loading done. [ 10.533262] PM: Read 578564 kbytes in 6.80 seconds (85.08 MB/s) [ 10.545313] Suspending console(s) (use no_console_suspend to debug) [ 193.721284] PM: freeze of devices complete after 7.891 msecs [ 193.722618] PM: late freeze of devices complete after 1.325 msecs [ 193.723969] PM: noirq freeze of devices complete after 1.343 msecs [ 193.724133] Disabling non-boot CPUs ... [ 193.724792] CPU1: shutdown [ 193.725387] PM: Creating hibernation image: [ 193.725387] PM: Need to copy 144499 pages [ 193.725439] Enabling non-boot CPUs ... [ 193.725783] CPU1: smp_ops.cpu_die() returned, trying to resuscitate [ 193.725790] CPU1: Booted secondary processor [ 193.726069] CPU1 is up [ 193.743772] PM: noirq restore of devices complete after 17.693 msecs [ 193.744691] PM: early restore of devices complete after 0.634 msecs [ 193.951382] [drm:omap_crtc_error_irq] *ERROR* tv: errors: 00008000 [ 193.951389] [drm:omap_plane_error_irq] *ERROR* gfx: errors: 00000040 [ 193.951402] [drm:omap_crtc_error_irq] *ERROR* tv: errors: 00008000 [ 193.951413] [drm:omap_crtc_error_irq] *ERROR* tv: errors: 00008000 [ 193.951424] [drm:omap_crtc_error_irq] *ERROR* tv: errors: 00008000 [ 193.951435] [drm:omap_crtc_error_irq] *ERROR* tv: errors: 00008000 [ 193.951445] [drm:omap_crtc_error_irq] *ERROR* tv: errors: 00008000 [ 193.951455] [drm:omap_crtc_error_irq] *ERROR* tv: errors: 00008000 [ 193.951465] [drm:omap_crtc_error_irq] *ERROR* tv: errors: 00008000 [ 193.951475] [drm:omap_crtc_error_irq] *ERROR* tv: errors: 00008000 [ 193.951484] [drm:omap_crtc_error_irq] *ERROR* tv: errors: 00008000 [ 193.951567] omap_l3_noc 44000000.ocp: L3 application error: target 2 mod:1 (unclearable) [ 193.951605] omap_l3_noc 44000000.ocp: L3 debug error: target 2 mod:1 (unclearable) [ 194.293226] ata1: SATA link down (SStatus 0 SControl 300) [ 194.560684] PM: restore of devices complete after 610.740 msecs -- regards, -grygorii -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html