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authorChris Wilson <chris@chris-wilson.co.uk>2009-10-20 16:29:16 +0000
committerEric Anholt <eric@anholt.net>2009-11-05 13:33:22 -0800
commitba86bf8bfc1add5f515db8cf1d6042bb9396a299 (patch)
treedd50b1d71536030c3a65e94993fc78bcdf4a7a46 /drivers/gpu
parent9a6fc8d0f8c3ee3d42417e8315fc8c8fae1d3213 (diff)
downloadlinux-ba86bf8bfc1add5f515db8cf1d6042bb9396a299.tar.bz2
drm/i915: Avoid potential sleep whilst holding spinlock
Miles Lane reported the following error: 2 locks held by cat/4179: #0: (&p->lock){+.+.+.}, at: [<c10a3884>] seq_read+0x25/0x315 #1: (&dev_priv->mm.active_list_lock){+.+...}, at: [<c119a854>] i915_batchbuffer_info+0x2b/0x124 Pid: 4179, comm: cat Not tainted 2.6.32-rc5-git1 #2 Call Trace: [<c104874f>] ? __debug_show_held_locks+0x1e/0x20 [<c1023fb0>] __might_sleep+0xf0/0xf7 [<c101c393>] kmap+0x17/0x58 [<c119a8d6>] i915_batchbuffer_info+0xad/0x124 [<c10a39bf>] seq_read+0x160/0x315 [<c108fb8c>] ? rw_verify_area+0x98/0xbb [<c10a385f>] ? seq_read+0x0/0x315 [<c1090331>] vfs_read+0x75/0xa9 [<c10903f9>] sys_read+0x3b/0x5d [<c1002a8f>] sysenter_do_call+0x12/0x36 The fix is relatively simple, use the atomic variants of kmap() that avoid the potential sleep. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Miles Lane <miles.lane@gmail.com> Signed-off-by: Eric Anholt <eric@anholt.net>
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/i915/i915_debugfs.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index f8ce9a3a420d..26bf0552b3cb 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -267,10 +267,10 @@ static void i915_dump_pages(struct seq_file *m, struct page **pages, int page_co
uint32_t *mem;
for (page = 0; page < page_count; page++) {
- mem = kmap(pages[page]);
+ mem = kmap_atomic(pages[page], KM_USER0);
for (i = 0; i < PAGE_SIZE; i += 4)
seq_printf(m, "%08x : %08x\n", i, mem[i / 4]);
- kunmap(pages[page]);
+ kunmap_atomic(pages[page], KM_USER0);
}
}