From b8dfa821c27046ede9bf8eb14cc8109d379428e9 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 7 Apr 2017 12:17:12 +0100 Subject: [PATCH] drm: Don't allow interruptions when opening debugfs/crc The code does not like to be interrupted when waiting for the first vblank after opening a debugfs/crc channel, so don't. [66285.716870] WARNING: CPU: 1 PID: 16615 at drivers/gpu/drm/drm_debugfs_crc.c:185 crtc_crc_open+0x1d0/0x1f0 [drm] [66285.716877] Modules linked in: i915 intel_powerclamp crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel cryptd intel_gtt i2c_algo_bit lpc_ich mfd_core drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops prime_numbers drm video button autofs4 sd_mod ahci libahci libata i2c_i801 scsi_mod i2c_designware_platform i2c_designware_core i2c_core [66285.716929] CPU: 1 PID: 16615 Comm: kms_frontbuffer Not tainted 4.11.0-rc5+ #7 [66285.716935] Hardware name: GIGABYTE GB-BXBT-1900/MZBAYAB-00, BIOS F8 03/02/2016 [66285.716941] Call Trace: [66285.716955] dump_stack+0x4d/0x6f [66285.716966] __warn+0xc1/0xe0 [66285.716975] warn_slowpath_null+0x18/0x20 [66285.717004] crtc_crc_open+0x1d0/0x1f0 [drm] [66285.717014] ? wake_atomic_t_function+0x50/0x50 [66285.717024] full_proxy_open+0xf0/0x1b0 [66285.717032] ? full_proxy_release+0x80/0x80 [66285.717042] do_dentry_open.isra.17+0x14b/0x2d0 [66285.717051] vfs_open+0x42/0x60 [66285.717064] path_openat+0x5e7/0x13d0 [66285.717074] ? refcount_dec_and_test+0x11/0x20 [66285.717081] ? down_read+0xd/0x30 [66285.717087] do_filp_open+0x85/0xf0 [66285.717093] ? __vfs_write+0x23/0x120 [66285.717100] ? __alloc_fd+0x3a/0x170 [66285.717107] do_sys_open+0x11e/0x1f0 [66285.717113] ? do_sys_open+0x11e/0x1f0 [66285.717119] SyS_openat+0xf/0x20 [66285.717125] entry_SYSCALL_64_fastpath+0x17/0x98 [66285.717131] RIP: 0033:0x7f5f2235146a [66285.717135] RSP: 002b:00007ffd892e6bc0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 [66285.717142] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5f2235146a [66285.717147] RDX: 0000000000000000 RSI: 00007ffd892e6c40 RDI: 0000000000000006 [66285.717151] RBP: 00007ffd892e6b20 R08: 0000000000000000 R09: 000000000000000f [66285.717156] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [66285.717161] R13: 00007ffd892e6b10 R14: 0000000000000004 R15: 00000000007e61f4 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100610 Fixes: e8fa5671183c ("drm: crc: Wait for a frame before returning from open()") Signed-off-by: Chris Wilson Cc: Tomeu Vizoso Cc: Daniel Vetter Reviewed-by: Tomeu Vizoso Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20170407111712.13962-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/drm_debugfs_crc.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/drivers/gpu/drm/drm_debugfs_crc.c b/drivers/gpu/drm/drm_debugfs_crc.c index 1722d8f21449..aa13e734c9e5 100644 --- a/drivers/gpu/drm/drm_debugfs_crc.c +++ b/drivers/gpu/drm/drm_debugfs_crc.c @@ -177,13 +177,9 @@ static int crtc_crc_open(struct inode *inode, struct file *filep) * guess when this particular piece of HW will be ready to start * generating CRCs. */ - ret = wait_event_interruptible_lock_irq(crc->wq, - crtc_crc_data_count(crc), - crc->lock); + wait_event_lock_irq(crc->wq, crtc_crc_data_count(crc), crc->lock); spin_unlock_irq(&crc->lock); - WARN_ON(ret); - return 0; err_disable: -- 2.20.1