Hi Sasha,

Please also pick [1] when it is applied.

--Sean

[1] https://lore.kernel.org/all/974d1b062d7c61ee6db00d16fa7c69aa1218ee02.1716198...

On 6/3/24 07:46, Sasha Levin wrote:

This is a note to let you know that I've just added the patch titled

drm: zynqmp_dpsub: Always register bridge

to the 6.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: drm-zynqmp_dpsub-always-register-bridge.patch and it can be found in the queue-6.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

commit d6817dc61b3b6a1e4f098b25109e7f2ecaaf0ee8 Author: Sean Anderson sean.anderson@linux.dev Date: Fri Mar 8 15:47:41 2024 -0500

drm: zynqmp_dpsub: Always register bridge

[ Upstream commit be3f3042391d061cfca2bd22630e0d101acea5fc ] We must always register the DRM bridge, since zynqmp_dp_hpd_work_func calls drm_bridge_hpd_notify, which in turn expects hpd_mutex to be initialized. We do this before zynqmp_dpsub_drm_init since that calls drm_bridge_attach. This fixes the following lockdep warning: [ 19.217084] ------------[ cut here ]------------ [ 19.227530] DEBUG_LOCKS_WARN_ON(lock->magic != lock) [ 19.227768] WARNING: CPU: 0 PID: 140 at kernel/locking/mutex.c:582 __mutex_lock+0x4bc/0x550 [ 19.241696] Modules linked in: [ 19.244937] CPU: 0 PID: 140 Comm: kworker/0:4 Not tainted 6.6.20+ #96 [ 19.252046] Hardware name: xlnx,zynqmp (DT) [ 19.256421] Workqueue: events zynqmp_dp_hpd_work_func [ 19.261795] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 19.269104] pc : __mutex_lock+0x4bc/0x550 [ 19.273364] lr : __mutex_lock+0x4bc/0x550 [ 19.277592] sp : ffffffc085c5bbe0 [ 19.281066] x29: ffffffc085c5bbe0 x28: 0000000000000000 x27: ffffff88009417f8 [ 19.288624] x26: ffffff8800941788 x25: ffffff8800020008 x24: ffffffc082aa3000 [ 19.296227] x23: ffffffc080d90e3c x22: 0000000000000002 x21: 0000000000000000 [ 19.303744] x20: 0000000000000000 x19: ffffff88002f5210 x18: 0000000000000000 [ 19.311295] x17: 6c707369642e3030 x16: 3030613464662072 x15: 0720072007200720 [ 19.318922] x14: 0000000000000000 x13: 284e4f5f4e524157 x12: 0000000000000001 [ 19.326442] x11: 0001ffc085c5b940 x10: 0001ff88003f388b x9 : 0001ff88003f3888 [ 19.334003] x8 : 0001ff88003f3888 x7 : 0000000000000000 x6 : 0000000000000000 [ 19.341537] x5 : 0000000000000000 x4 : 0000000000001668 x3 : 0000000000000000 [ 19.349054] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffffff88003f3880 [ 19.356581] Call trace: [ 19.359160] __mutex_lock+0x4bc/0x550 [ 19.363032] mutex_lock_nested+0x24/0x30 [ 19.367187] drm_bridge_hpd_notify+0x2c/0x6c [ 19.371698] zynqmp_dp_hpd_work_func+0x44/0x54 [ 19.376364] process_one_work+0x3ac/0x988 [ 19.380660] worker_thread+0x398/0x694 [ 19.384736] kthread+0x1bc/0x1c0 [ 19.388241] ret_from_fork+0x10/0x20 [ 19.392031] irq event stamp: 183 [ 19.395450] hardirqs last enabled at (183): [<ffffffc0800b9278>] finish_task_switch.isra.0+0xa8/0x2d4 [ 19.405140] hardirqs last disabled at (182): [<ffffffc081ad3754>] __schedule+0x714/0xd04 [ 19.413612] softirqs last enabled at (114): [<ffffffc080133de8>] srcu_invoke_callbacks+0x158/0x23c [ 19.423128] softirqs last disabled at (110): [<ffffffc080133de8>] srcu_invoke_callbacks+0x158/0x23c [ 19.432614] ---[ end trace 0000000000000000 ]--- Fixes: eb2d64bfcc17 ("drm: xlnx: zynqmp_dpsub: Report HPD through the bridge") Signed-off-by: Sean Anderson sean.anderson@linux.dev Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Reviewed-by: Tomi Valkeinen tomi.valkeinen@ideasonboard.com Signed-off-by: Tomi Valkeinen tomi.valkeinen@ideasonboard.com Link: https://patchwork.freedesktop.org/patch/msgid/20240308204741.3631919-1-sean.... (cherry picked from commit 61ba791c4a7a09a370c45b70a81b8c7d4cf6b2ae) Signed-off-by: Maarten Lankhorst maarten.lankhorst@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org

diff --git a/drivers/gpu/drm/xlnx/zynqmp_dpsub.c b/drivers/gpu/drm/xlnx/zynqmp_dpsub.c index 88eb33acd5f0d..face8d6b2a6fb 100644 --- a/drivers/gpu/drm/xlnx/zynqmp_dpsub.c +++ b/drivers/gpu/drm/xlnx/zynqmp_dpsub.c @@ -256,12 +256,12 @@ static int zynqmp_dpsub_probe(struct platform_device *pdev) if (ret) goto err_dp;

• drm_bridge_add(dpsub->bridge);
• if (dpsub->dma_enabled) { ret = zynqmp_dpsub_drm_init(dpsub); if (ret) goto err_disp;

• } else {

• drm_bridge_add(dpsub->bridge);
  

  }

dev_info(&pdev->dev, "ZynqMP DisplayPort Subsystem driver probed"); @@ -288,9 +288,8 @@ static void zynqmp_dpsub_remove(struct platform_device *pdev) if (dpsub->drm) zynqmp_dpsub_drm_cleanup(dpsub);

• else

• drm_bridge_remove(dpsub->bridge);
  

• drm_bridge_remove(dpsub->bridge); zynqmp_disp_remove(dpsub); zynqmp_dp_remove(dpsub);