From d5f1b01644b6fd5e9eb480a4762cd6b569cb1246 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Mon, 8 Oct 2007 11:48:57 -0300 Subject: [PATCH] V4L/DVB (6291): Fix: avoid oops on some SMP machines This workaround fix a bug that happens on some SMP machines. On those machines, videobuf_iolock is called too soon, before file .mmap handler. This patch calls the scheduler before iolocking, allowing it to properly call the pending mmap. Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/videobuf-core.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c index 8e4026e6fae3..aa402abc4b0c 100644 --- a/drivers/media/video/videobuf-core.c +++ b/drivers/media/video/videobuf-core.c @@ -94,6 +94,14 @@ int videobuf_iolock(struct videobuf_queue* q, struct videobuf_buffer *vb, MAGIC_CHECK(vb->magic,MAGIC_BUFFER); MAGIC_CHECK(q->int_ops->magic,MAGIC_QTYPE_OPS); + /* FIXME: This is required to avoid OOPS on some cases, since mmap_mapper() + method should be called before _iolock. + On some cases, the mmap_mapper() is called only after scheduling. + + However, this way is just too dirty! Better to wait for some event. + */ + schedule_timeout(HZ); + return CALL(q,iolock,q,vb,fbuf); } -- 2.34.1