[PATCH 0/2] drm: bridge: adv7511: two fixes for CEC

[PATCH 0/2] drm: bridge: adv7511: two fixes for CEC

[Alvin Šipraga]

From: Alvin Šipraga <alsi@bang-olufsen.dk>

The patches are sent against drm-misc-next. Thanks!

Alvin Šipraga (2):
  drm: bridge: adv7511: fix CEC power down control register offset
  drm: bridge: adv7511: unregister cec i2c device after cec adapter

 drivers/gpu/drm/bridge/adv7511/adv7511.h     | 5 +----
 drivers/gpu/drm/bridge/adv7511/adv7511_cec.c | 4 ++--
 drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 5 ++---
 3 files changed, 5 insertions(+), 9 deletions(-)

-- 
2.35.1

[PATCH 1/2] drm: bridge: adv7511: fix CEC power down control register offset

[Alvin Šipraga]

From: Alvin Šipraga <alsi@bang-olufsen.dk>

The ADV7511_REG_CEC_CTRL = 0xE2 register is part of the main register
map - not the CEC register map. As such, we shouldn't apply an offset to
the register address. Doing so will cause us to address a bogus register
for chips with a CEC register map offset (e.g. ADV7533).

Fixes: 3b1b975003e4 ("drm: adv7511/33: add HDMI CEC support")
Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk>
---
 drivers/gpu/drm/bridge/adv7511/adv7511.h     | 5 +----
 drivers/gpu/drm/bridge/adv7511/adv7511_cec.c | 4 ++--
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511.h b/drivers/gpu/drm/bridge/adv7511/adv7511.h
index 592ecfcf00ca..4e7cbaa9204f 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7511.h
+++ b/drivers/gpu/drm/bridge/adv7511/adv7511.h
@@ -386,10 +386,7 @@ void adv7511_cec_irq_process(struct adv7511 *adv7511, unsigned int irq1);
 #else
 static inline int adv7511_cec_init(struct device *dev, struct adv7511 *adv7511)
 {
-	unsigned int offset = adv7511->type == ADV7533 ?
-						ADV7533_REG_CEC_OFFSET : 0;
-
-	regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset,
+	regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL,
 		     ADV7511_CEC_CTRL_POWER_DOWN);
 	return 0;
 }
diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_cec.c b/drivers/gpu/drm/bridge/adv7511/adv7511_cec.c
index 28d9becc939c..4ee7f2e911e3 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7511_cec.c
+++ b/drivers/gpu/drm/bridge/adv7511/adv7511_cec.c
@@ -303,7 +303,7 @@ int adv7511_cec_init(struct device *dev, struct adv7511 *adv7511)
 		goto err_cec_alloc;
 	}
 
-	regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset, 0);
+	regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL, 0);
 	/* cec soft reset */
 	regmap_write(adv7511->regmap_cec,
 		     ADV7511_REG_CEC_SOFT_RESET + offset, 0x01);
@@ -330,7 +330,7 @@ int adv7511_cec_init(struct device *dev, struct adv7511 *adv7511)
 	dev_info(dev, "Initializing CEC failed with error %d, disabling CEC\n",
 		 ret);
 err_cec_parse_dt:
-	regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset,
+	regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL,
 		     ADV7511_CEC_CTRL_POWER_DOWN);
 	return ret == -EPROBE_DEFER ? ret : 0;
 }
-- 
2.35.1

[PATCH 2/2] drm: bridge: adv7511: unregister cec i2c device after cec adapter

[Alvin Šipraga]

From: Alvin Šipraga <alsi@bang-olufsen.dk>

cec_unregister_adapter() assumes that the underlying adapter ops are
callable. For example, if the CEC adapter currently has a valid physical
address, then the unregistration procedure will invalidate the physical
address by setting it to f.f.f.f. Whence the following kernel oops
observed after removing the adv7511 module:

    Unable to handle kernel execution of user memory at virtual address 0000000000000000
    Internal error: Oops: 86000004 [#1] PREEMPT_RT SMP
    Call trace:
     0x0
     adv7511_cec_adap_log_addr+0x1ac/0x1c8 [adv7511]
     cec_adap_unconfigure+0x44/0x90 [cec]
     __cec_s_phys_addr.part.0+0x68/0x230 [cec]
     __cec_s_phys_addr+0x40/0x50 [cec]
     cec_unregister_adapter+0xb4/0x118 [cec]
     adv7511_remove+0x60/0x90 [adv7511]
     i2c_device_remove+0x34/0xe0
     device_release_driver_internal+0x114/0x1f0
     driver_detach+0x54/0xe0
     bus_remove_driver+0x60/0xd8
     driver_unregister+0x34/0x60
     i2c_del_driver+0x2c/0x68
     adv7511_exit+0x1c/0x67c [adv7511]
     __arm64_sys_delete_module+0x154/0x288
     invoke_syscall+0x48/0x100
     el0_svc_common.constprop.0+0x48/0xe8
     do_el0_svc+0x28/0x88
     el0_svc+0x1c/0x50
     el0t_64_sync_handler+0xa8/0xb0
     el0t_64_sync+0x15c/0x160
    Code: bad PC value
    ---[ end trace 0000000000000000 ]---

Protect against this scenario by unregistering i2c_cec after
unregistering the CEC adapter. Duly disable the CEC clock afterwards
too.

Fixes: 3b1b975003e4 ("drm: adv7511/33: add HDMI CEC support")
Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk>
---
 drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
index f8e5da148599..2628f1abe413 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
+++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
@@ -1314,9 +1314,6 @@ static int adv7511_remove(struct i2c_client *i2c)
 {
 	struct adv7511 *adv7511 = i2c_get_clientdata(i2c);
 
-	i2c_unregister_device(adv7511->i2c_cec);
-	clk_disable_unprepare(adv7511->cec_clk);
-
 	adv7511_uninit_regulators(adv7511);
 
 	drm_bridge_remove(&adv7511->bridge);
@@ -1324,6 +1321,8 @@ static int adv7511_remove(struct i2c_client *i2c)
 	adv7511_audio_exit(adv7511);
 
 	cec_unregister_adapter(adv7511->cec_adap);
+	i2c_unregister_device(adv7511->i2c_cec);
+	clk_disable_unprepare(adv7511->cec_clk);
 
 	i2c_unregister_device(adv7511->i2c_packet);
 	i2c_unregister_device(adv7511->i2c_edid);
-- 
2.35.1

Re: [PATCH 0/2] drm: bridge: adv7511: two fixes for CEC

[Alvin Šipraga]

Alvin Šipraga <alvin@pqrs.dk> writes:

> From: Alvin Šipraga <alsi@bang-olufsen.dk>
>
> The patches are sent against drm-misc-next. Thanks!

Whoops, I meant drm-misc-fixes, since these are fixes. :-)

Separate patches aimed at drm-misc-next incoming.

>
> Alvin Šipraga (2):
>   drm: bridge: adv7511: fix CEC power down control register offset
>   drm: bridge: adv7511: unregister cec i2c device after cec adapter
>
>  drivers/gpu/drm/bridge/adv7511/adv7511.h     | 5 +----
>  drivers/gpu/drm/bridge/adv7511/adv7511_cec.c | 4 ++--
>  drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 5 ++---
>  3 files changed, 5 insertions(+), 9 deletions(-)