This is a note to let you know that I've just added the patch titled drm/dp/mst: make sure mst_primary mstb is valid in work function to the 4.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-dp-mst-make-sure-mst_primary-mstb-is-valid-in-work-function.patch and it can be found in the queue-4.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 9254ec496a1dbdddeab50021a8138dc627a8166a Mon Sep 17 00:00:00 2001 From: Daniel Vetter <daniel.vetter@xxxxxxxx> Date: Mon, 22 Jun 2015 17:31:59 +1000 Subject: drm/dp/mst: make sure mst_primary mstb is valid in work function From: Daniel Vetter <daniel.vetter@xxxxxxxx> commit 9254ec496a1dbdddeab50021a8138dc627a8166a upstream. This validates the mst_primary under the lock, and then calls into the check and send function. This makes the code a lot easier to understand the locking rules in. Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx> Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/drm_dp_mst_topology.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1200,7 +1200,7 @@ static void drm_dp_check_and_send_link_a struct drm_dp_mst_branch *mstb) { struct drm_dp_mst_port *port; - + struct drm_dp_mst_branch *mstb_child; if (!mstb->link_address_sent) { drm_dp_send_link_address(mgr, mstb); mstb->link_address_sent = true; @@ -1215,17 +1215,31 @@ static void drm_dp_check_and_send_link_a if (!port->available_pbn) drm_dp_send_enum_path_resources(mgr, mstb, port); - if (port->mstb) - drm_dp_check_and_send_link_address(mgr, port->mstb); + if (port->mstb) { + mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb); + if (mstb_child) { + drm_dp_check_and_send_link_address(mgr, mstb_child); + drm_dp_put_mst_branch_device(mstb_child); + } + } } } static void drm_dp_mst_link_probe_work(struct work_struct *work) { struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work); + struct drm_dp_mst_branch *mstb; - drm_dp_check_and_send_link_address(mgr, mgr->mst_primary); - + mutex_lock(&mgr->lock); + mstb = mgr->mst_primary; + if (mstb) { + kref_get(&mstb->kref); + } + mutex_unlock(&mgr->lock); + if (mstb) { + drm_dp_check_and_send_link_address(mgr, mstb); + drm_dp_put_mst_branch_device(mstb); + } } static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, Patches currently in stable-queue which might be from daniel.vetter@xxxxxxxx are queue-4.1/drm-vgem-set-unique-to-vgem.patch queue-4.1/drm-dp-mst-take-lock-around-looking-up-the-branch-device-on-hpd-irq.patch queue-4.1/drm-i915-declare-the-swizzling-unknown-for-l-shaped-configurations.patch queue-4.1/drm-dp-mst-make-sure-mst_primary-mstb-is-valid-in-work-function.patch queue-4.1/drm-provide-compat-ioctl-for-addfb2.1.patch queue-4.1/drm-atomic-fix-out-of-bounds-read-in-for_each_-_in_state-helpers.patch queue-4.1/revert-drm-i915-declare-the-swizzling-unknown-for-l-shaped-configurations.patch queue-4.1/drm-i915-forward-all-core-drm-ioctls-to-core-compat-handling.patch queue-4.1/drm-stop-resetting-connector-state-to-unknown.patch queue-4.1/drm-i915-snapshot-seqno-of-most-recently-submitted-request.patch queue-4.1/drm-i915-use-two-32bit-reads-for-select-64bit-reg_read-ioctls.patch queue-4.1/drm-rockchip-use-drm_gem_mmap-helpers.patch queue-4.1/drm-dp-mst-close-deadlock-in-connector-destruction.patch queue-4.1/drm-add-a-check-for-x-y-in-drm_mode_setcrtc.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html