Hi,
On 19/09/2023 16:37, H. Nikolaus Schaller wrote:
dsi_init_output() called by dsi_probe() may fail. In that
case mipi_dsi_host_unregister() is called which may call
omap_dsi_host_detach() with uninitialized dsi->dsidev
because omap_dsi_host_attach() was never called before.
This happens if the panel driver asks for an EPROBE_DEFER.
So let's suppress the WARN() in this special case.
[ 7.416759] WARNING: CPU: 0 PID: 32 at drivers/gpu/drm/omapdrm/dss/dsi.c:4419 omap_dsi_host_detach+0x3c/0xbc [omapdrm]
[ 7.436053] Modules linked in: ina2xx_adc snd_soc_ts3a227e bq2429x_charger bq27xxx_battery_i2c(+) bq27xxx_battery ina2xx tca8418_keypad as5013(+) omapdrm hci_uart cec palmas_pwrbutton btbcm bmp280_spi palmas_gpadc bluetooth usb3503 ecdh_generic bmc150_accel_i2c bmg160_i2c ecc bmc150_accel_core bmg160_core bmc150_magn_i2c bmp280_i2c bmc150_magn bno055 industrialio_triggered_buffer bmp280 kfifo_buf snd_soc_omap_aess display_connector drm_kms_helper syscopyarea snd_soc_omap_mcbsp snd_soc_ti_sdma sysfillrect ti_tpd12s015 sysimgblt fb_sys_fops wwan_on_off snd_soc_gtm601 generic_adc_battery drm snd_soc_w2cbw003_bt industrialio drm_panel_orientation_quirks pwm_bl pwm_omap_dmtimer ip_tables x_tables ipv6 autofs4
[ 7.507068] CPU: 0 PID: 32 Comm: kworker/u4:2 Tainted: G W 6.1.0-rc3-letux-lpae+ #11107
[ 7.516964] Hardware name: Generic OMAP5 (Flattened Device Tree)
[ 7.523284] Workqueue: events_unbound deferred_probe_work_func
[ 7.529456] unwind_backtrace from show_stack+0x10/0x14
[ 7.534972] show_stack from dump_stack_lvl+0x40/0x4c
[ 7.540315] dump_stack_lvl from __warn+0xb0/0x164
[ 7.545379] __warn from warn_slowpath_fmt+0x70/0x9c
[ 7.550625] warn_slowpath_fmt from omap_dsi_host_detach+0x3c/0xbc [omapdrm]
[ 7.558137] omap_dsi_host_detach [omapdrm] from mipi_dsi_remove_device_fn+0x10/0x20
[ 7.566376] mipi_dsi_remove_device_fn from device_for_each_child+0x60/0x94
[ 7.573729] device_for_each_child from mipi_dsi_host_unregister+0x20/0x54
[ 7.580992] mipi_dsi_host_unregister from dsi_probe+0x5d8/0x744 [omapdrm]
[ 7.588315] dsi_probe [omapdrm] from platform_probe+0x58/0xa8
[ 7.594542] platform_probe from really_probe+0x144/0x2ac
[ 7.600249] really_probe from __driver_probe_device+0xc4/0xd8
[ 7.606411] __driver_probe_device from driver_probe_device+0x3c/0xb8
[ 7.613216] driver_probe_device from __device_attach_driver+0x58/0xbc
[ 7.620115] __device_attach_driver from bus_for_each_drv+0xa0/0xb4
[ 7.626737] bus_for_each_drv from __device_attach+0xdc/0x150
[ 7.632808] __device_attach from bus_probe_device+0x28/0x80
[ 7.638792] bus_probe_device from deferred_probe_work_func+0x84/0xa0
[ 7.645595] deferred_probe_work_func from process_one_work+0x1a4/0x2d8
[ 7.652587] process_one_work from worker_thread+0x214/0x2b8
[ 7.658567] worker_thread from kthread+0xe4/0xf0
[ 7.663542] kthread from ret_from_fork+0x14/0x1c
[ 7.668515] Exception stack(0xf01b5fb0 to 0xf01b5ff8)
[ 7.673827] 5fa0: 00000000 00000000 00000000 00000000
[ 7.682435] 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 7.691038] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
---
drivers/gpu/drm/omapdrm/dss/dsi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
index ea63c64d3a1ab..c37eb6b1b9a39 100644
--- a/drivers/gpu/drm/omapdrm/dss/dsi.c
+++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
@@ -4411,7 +4411,7 @@ static int omap_dsi_host_detach(struct mipi_dsi_host *host,
{
struct dsi_data *dsi = host_to_omap(host);
- if (WARN_ON(dsi->dsidev != client))
+ if (!dsi->dsidev || WARN_ON(dsi->dsidev != client))
return -EINVAL;
cancel_delayed_work_sync(&dsi->dsi_disable_work);
I sent a patch to the DSI framework code,
"[PATCH] drm/mipi-dsi: Fix detach call without attach".
If that fixes the issue (please test, I don't have a suitable platform),
perhaps it's a better fix as detach really shouldn't be called if attach
has not been called.
Tomi
