From 09b4ea47d1041612b101c369969db123ac2c1511 Mon Sep 17 00:00:00 2001 From: Ilija Hadzic Date: Fri, 28 Oct 2011 17:43:28 -0400 Subject: drm: make DRM_UNLOCKED ioctls with their own mutex drm_getclient, drm_getstats and drm_getmap (with a few minor adjustments) do not need global mutex, so fix that and make the said ioctls DRM_UNLOCKED. Details: drm_getclient: the only thing that should be protected here is dev->filelist and that is already protected everywhere with dev->struct_mutex. drm_getstats: there is no need for any mutex here because the loop runs through quasi-static (set at load time only) data, and the actual count access is done with atomic_read() drm_getmap already uses dev->struct_mutex to protect dev->maplist, which also used to protect the same structure everywhere else except at three places: * drm_getsarea, which doesn't grab *any* mutex before touching dev->maplist (so no drm_global_mutex doesn't help here either; different issue for a different patch). However, drivers seem to call it only at initialization time so it probably doesn't matter * drm_master_destroy, which is called from drm_master_put, which in turn is protected with dev->struct_mutex everywhere else in drm module, so we are good here too. * drm_getsareactx, which releases the dev->struct_mutex too early, but this patch includes the fix for that. v2: * incorporate comments received from Daniel Vetter * include the (long) explanation above to make it clear what we are doing (and why), also at Daniel Vetter's request * tighten up mutex grab/release locations to only encompass real critical sections, rather than some random code around them Signed-off-by: Ilija Hadzic Reviewed-by: Daniel Vetter Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_context.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/drm_context.c') diff --git a/drivers/gpu/drm/drm_context.c b/drivers/gpu/drm/drm_context.c index 6d440fb894cf..325365f6d355 100644 --- a/drivers/gpu/drm/drm_context.c +++ b/drivers/gpu/drm/drm_context.c @@ -154,8 +154,6 @@ int drm_getsareactx(struct drm_device *dev, void *data, return -EINVAL; } - mutex_unlock(&dev->struct_mutex); - request->handle = NULL; list_for_each_entry(_entry, &dev->maplist, head) { if (_entry->map == map) { @@ -164,6 +162,9 @@ int drm_getsareactx(struct drm_device *dev, void *data, break; } } + + mutex_unlock(&dev->struct_mutex); + if (request->handle == NULL) return -EINVAL; -- cgit v1.2.3-73-gaa49b