diff options
| author | Luca Leonardo Scorcia <l.scorcia@gmail.com> | 2026-02-25 09:38:41 +0000 |
|---|---|---|
| committer | Chun-Kuang Hu <chunkuang.hu@kernel.org> | 2026-03-22 14:15:44 +0000 |
| commit | 4cfdfeb6ac06079f92fccd977fa742d6c5b8dd3a (patch) | |
| tree | 0caff2fd30bb6810c6f2f68cb50c1a8bd95c604c | |
| parent | 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f (diff) | |
drm/mediatek: dsi: Store driver data before invoking mipi_dsi_host_register
The call to mipi_dsi_host_register triggers a callback to mtk_dsi_bind,
which uses dev_get_drvdata to retrieve the mtk_dsi struct, so this
structure needs to be stored inside the driver data before invoking it.
As drvdata is currently uninitialized it leads to a crash when
registering the DSI DRM encoder right after acquiring
the mode_config.idr_mutex, blocking all subsequent DRM operations.
Fixes the following crash during mediatek-drm probe (tested on Xiaomi
Smart Clock x04g):
Unable to handle kernel NULL pointer dereference at virtual address
0000000000000040
[...]
Modules linked in: mediatek_drm(+) drm_display_helper cec drm_client_lib
drm_dma_helper drm_kms_helper panel_simple
[...]
Call trace:
drm_mode_object_add+0x58/0x98 (P)
__drm_encoder_init+0x48/0x140
drm_encoder_init+0x6c/0xa0
drm_simple_encoder_init+0x20/0x34 [drm_kms_helper]
mtk_dsi_bind+0x34/0x13c [mediatek_drm]
component_bind_all+0x120/0x280
mtk_drm_bind+0x284/0x67c [mediatek_drm]
try_to_bring_up_aggregate_device+0x23c/0x320
__component_add+0xa4/0x198
component_add+0x14/0x20
mtk_dsi_host_attach+0x78/0x100 [mediatek_drm]
mipi_dsi_attach+0x2c/0x50
panel_simple_dsi_probe+0x4c/0x9c [panel_simple]
mipi_dsi_drv_probe+0x1c/0x28
really_probe+0xc0/0x3dc
__driver_probe_device+0x80/0x160
driver_probe_device+0x40/0x120
__device_attach_driver+0xbc/0x17c
bus_for_each_drv+0x88/0xf0
__device_attach+0x9c/0x1cc
device_initial_probe+0x54/0x60
bus_probe_device+0x34/0xa0
device_add+0x5b0/0x800
mipi_dsi_device_register_full+0xdc/0x16c
mipi_dsi_host_register+0xc4/0x17c
mtk_dsi_probe+0x10c/0x260 [mediatek_drm]
platform_probe+0x5c/0xa4
really_probe+0xc0/0x3dc
__driver_probe_device+0x80/0x160
driver_probe_device+0x40/0x120
__driver_attach+0xc8/0x1f8
bus_for_each_dev+0x7c/0xe0
driver_attach+0x24/0x30
bus_add_driver+0x11c/0x240
driver_register+0x68/0x130
__platform_register_drivers+0x64/0x160
mtk_drm_init+0x24/0x1000 [mediatek_drm]
do_one_initcall+0x60/0x1d0
do_init_module+0x54/0x240
load_module+0x1838/0x1dc0
init_module_from_file+0xd8/0xf0
__arm64_sys_finit_module+0x1b4/0x428
invoke_syscall.constprop.0+0x48/0xc8
do_el0_svc+0x3c/0xb8
el0_svc+0x34/0xe8
el0t_64_sync_handler+0xa0/0xe4
el0t_64_sync+0x198/0x19c
Code: 52800022 941004ab 2a0003f3 37f80040 (29005a80)
Fixes: e4732b590a77 ("drm/mediatek: dsi: Register DSI host after acquiring clocks and PHY")
Signed-off-by: Luca Leonardo Scorcia <l.scorcia@gmail.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20260225094047.76780-1-l.scorcia@gmail.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
| -rw-r--r-- | drivers/gpu/drm/mediatek/mtk_dsi.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c index 17c67f02016b..aaf6c9ebd319 100644 --- a/drivers/gpu/drm/mediatek/mtk_dsi.c +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c @@ -1236,6 +1236,11 @@ static int mtk_dsi_probe(struct platform_device *pdev) dsi->host.ops = &mtk_dsi_ops; dsi->host.dev = dev; + + init_waitqueue_head(&dsi->irq_wait_queue); + + platform_set_drvdata(pdev, dsi); + ret = mipi_dsi_host_register(&dsi->host); if (ret < 0) return dev_err_probe(dev, ret, "Failed to register DSI host\n"); @@ -1247,10 +1252,6 @@ static int mtk_dsi_probe(struct platform_device *pdev) return dev_err_probe(&pdev->dev, ret, "Failed to request DSI irq\n"); } - init_waitqueue_head(&dsi->irq_wait_queue); - - platform_set_drvdata(pdev, dsi); - dsi->bridge.of_node = dev->of_node; dsi->bridge.type = DRM_MODE_CONNECTOR_DSI; |