From 1b6e5fd5f4fc152064f4f71cea0bcfeb49e29b8b Mon Sep 17 00:00:00 2001 From: Maarten Lankhorst Date: Wed, 10 Jul 2013 12:26:56 +0200 Subject: [PATCH] drm/radeon: add missing ttm_eu_backoff_reservation to radeon_bo_list_validate Op 10-07-13 12:03, Markus Trippelsdorf schreef: > On 2013.07.10 at 11:56 +0200, Maarten Lankhorst wrote: >> Op 10-07-13 11:46, Markus Trippelsdorf schreef: >>> On 2013.07.10 at 11:29 +0200, Maarten Lankhorst wrote: >>>> Op 10-07-13 11:22, Markus Trippelsdorf schreef: >>>>> By simply copy/pasting a big document under LibreOffice my system hangs >>>>> itself up. Only a hard reset gets it working again. >>>>> see also: https://bugs.freedesktop.org/show_bug.cgi?id=66551 >>>>> >>>>> I've bisected the issue to: >>>>> >>>>> commit ecff665f5e3f1c6909353e00b9420e45ae23d995 >>>>> Author: Maarten Lankhorst >>>>> Date: Thu Jun 27 13:48:17 2013 +0200 >>>>> >>>>> drm/ttm: make ttm reservation calls behave like reservation calls >>>>> >>>>> This commit converts the source of the val_seq counter to >>>>> the ww_mutex api. The reservation objects are converted later, >>>>> because there is still a lockdep splat in nouveau that has to >>>>> resolved first. >>>>> >>>>> Signed-off-by: Maarten Lankhorst >>>>> Reviewed-by: Jerome Glisse >>>>> Signed-off-by: Dave Airlie >>>> Hey, >>>> >>>> Can you try current head with CONFIG_PROVE_LOCKING set and post the >>>> lockdep splat from dmesg, if any? If there is any locking issue >>>> lockdep should warn about it. Lockdep will turn itself off after the >>>> first splat, so if the lockdep splat happens before running the >>>> affected parts those will have to be fixed first. >>> There was an unrelated EDAC lockdep splat, so I simply disabled it. >>> >>> This is what I get: >>> >>> Jul 10 11:40:44 x4 kernel: ================================================ >>> Jul 10 11:40:44 x4 kernel: [ BUG: lock held when returning to user space! ] >>> Jul 10 11:40:44 x4 kernel: 3.10.0-08587-g496322b #35 Not tainted >>> Jul 10 11:40:44 x4 kernel: ------------------------------------------------ >>> Jul 10 11:40:44 x4 kernel: X/211 is leaving the kernel with locks still held! >>> Jul 10 11:40:44 x4 kernel: 2 locks held by X/211: >>> Jul 10 11:40:44 x4 kernel: #0: (reservation_ww_class_acquire){+.+.+.}, at: [] radeon_bo_list_validate+0x20/0xd0 >>> Jul 10 11:40:44 x4 kernel: #1: (reservation_ww_class_mutex){+.+.+.}, at: [] ttm_eu_reserve_buffers+0x126/0x4b0 >>> Jul 10 11:40:52 x4 kernel: SysRq : Emergency Sync >>> Jul 10 11:40:53 x4 kernel: Emergency Sync complete >>> >> Thanks, exactly what I thought. I missed a backoff somewhere.. >> >> Does the below patch fix it? > Yes. Thank you for your quick reply. 8<------ If radeon_cs_parser_relocs fails ttm_eu_backoff_reservation doesn't get called. This left open a bug where ttm_eu_reserve_buffers succeeded but the bo's were not unlocked afterwards: Jul 10 11:40:44 x4 kernel: ================================================ Jul 10 11:40:44 x4 kernel: [ BUG: lock held when returning to user space! ] Jul 10 11:40:44 x4 kernel: 3.10.0-08587-g496322b #35 Not tainted Jul 10 11:40:44 x4 kernel: ------------------------------------------------ Jul 10 11:40:44 x4 kernel: X/211 is leaving the kernel with locks still held! Jul 10 11:40:44 x4 kernel: 2 locks held by X/211: Jul 10 11:40:44 x4 kernel: #0: (reservation_ww_class_acquire){+.+.+.}, at: [] radeon_bo_list_validate+0x20/0xd0 Jul 10 11:40:44 x4 kernel: #1: (reservation_ww_class_mutex){+.+.+.}, at: [] ttm_eu_reserve_buffers+0x126/0x4b0 Jul 10 11:40:52 x4 kernel: SysRq : Emergency Sync Jul 10 11:40:53 x4 kernel: Emergency Sync complete This is a regression caused by commit ecff665f5e. "drm/ttm: make ttm reservation calls behave like reservation calls" Reported-by: Markus Trippelsdorf Tested-by: Markus Trippelsdorf Signed-off-by: Maarten Lankhorst Signed-off-by: Alex Deucher --- drivers/gpu/drm/radeon/radeon_object.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c index 0219d263e2df..2020bf4a3830 100644 --- a/drivers/gpu/drm/radeon/radeon_object.c +++ b/drivers/gpu/drm/radeon/radeon_object.c @@ -377,6 +377,7 @@ int radeon_bo_list_validate(struct ww_acquire_ctx *ticket, domain = lobj->alt_domain; goto retry; } + ttm_eu_backoff_reservation(ticket, head); return r; } } -- GitLab