Hi Sasha, Please also pick [1] when it is applied. --Sean [1] https://lore.kernel.org/all/974d1b062d7c61ee6db00d16fa7c69aa1218ee02.1716198025.git.christophe.jaillet@xxxxxxxxxx/ 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;a=summary > > 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@xxxxxxxxxxxxxxx> know about it. > > > > commit d6817dc61b3b6a1e4f098b25109e7f2ecaaf0ee8 > Author: Sean Anderson <sean.anderson@xxxxxxxxx> > 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@xxxxxxxxx> > Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > Reviewed-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx> > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx> > Link: https://patchwork.freedesktop.org/patch/msgid/20240308204741.3631919-1-sean.anderson@xxxxxxxxx > (cherry picked from commit 61ba791c4a7a09a370c45b70a81b8c7d4cf6b2ae) > Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > > 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); >