Re: [PATCH] drm/msm/mdp5: fix kernel panic during shutdown

2022-09-12 Thread Abhinav Kumar

Hi Fabien

Thanks for the patch.

I believe this issue should get resolved with 
https://patchwork.freedesktop.org/patch/490326/ as this avoids the override.


I have acked that change and will pick it up for the next fixes.

Thanks

Abhinav


On 9/9/2022 8:28 AM, Fabien Parent wrote:

The kernel is panicking when rebooting on MSM8939:

# reboot -f
[   87.280853] Unable to handle kernel write to read-only memory at 
virtual address 88ed5810
...
snip
...
[   87.445142] Call trace:
[   87.452253]  mutex_lock+0x1c/0x50
[   87.454511]  msm_drv_shutdown+0x28/0x40
[   87.457984]  platform_shutdown+0x28/0x40
[   87.461629]  device_shutdown+0x14c/0x240
[   87.465796]  __do_sys_reboot+0x180/0x274
[   87.469703]  __arm64_sys_reboot+0x28/0x3c
[   87.473608]  invoke_syscall+0x54/0x124
[   87.477515]  el0_svc_common.constprop.0+0x44/0xec
[   87.481163]  do_el0_svc+0x90/0xe0
[   87.485934]  el0_svc+0x50/0xa4
[   87.489232]  el0t_64_sync_handler+0x11c/0x150
[   87.492185]  el0t_64_sync+0x190/0x194
[   87.496618] Code: f9800011 c85ffc03 ca010064 b564 (c8047c02)
[   87.500264] ---[ end trace  ]---
Segmentation fault

The issue comes from the fact that mdp5_init() is calling
platform_set_drvdata() and consequently overwriting the driver data
previously set by msm_drv_probe.
msm_drv_shutdown was casting the driver data as "struct msm_drm_private"
while it was actually a "struct mdp5_kms".

This commit fixes the issue by having mdp5_init() not override the
platform driver data, and instead use a series of
to_mdp5_kms(to_mdp_kms(priv->kms)) to retrieve the mdp5_kms from the
pdata.

Fixes: 54199009958f ("drm/msm: Fix shutdown")
Signed-off-by: Fabien Parent 
---
  drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c | 18 +++---
  1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c 
b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
index d2a48caf9d27..17aeabeedfeb 100644
--- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
+++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
@@ -634,7 +634,8 @@ static int mdp5_kms_init(struct drm_device *dev)
  
  static void mdp5_destroy(struct platform_device *pdev)

  {
-   struct mdp5_kms *mdp5_kms = platform_get_drvdata(pdev);
+   struct msm_drm_private *priv = platform_get_drvdata(pdev);
+   struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
int i;
  
  	if (mdp5_kms->ctlm)

@@ -797,7 +798,8 @@ static int mdp5_init(struct platform_device *pdev, struct 
drm_device *dev)
goto fail;
}
  
-	platform_set_drvdata(pdev, mdp5_kms);

+   /* set uninit-ed kms */
+   priv->kms = _kms->base.base;
  
  	spin_lock_init(_kms->resource_lock);
  
@@ -890,13 +892,13 @@ static int mdp5_init(struct platform_device *pdev, struct drm_device *dev)

if (ret)
goto fail;
  
-	/* set uninit-ed kms */

-   priv->kms = _kms->base.base;
-
return 0;
  fail:
if (mdp5_kms)
mdp5_destroy(pdev);
+
+   priv->kms = NULL;
+
return ret;
  }
  
@@ -956,7 +958,8 @@ static int mdp5_dev_remove(struct platform_device *pdev)

  static __maybe_unused int mdp5_runtime_suspend(struct device *dev)
  {
struct platform_device *pdev = to_platform_device(dev);
-   struct mdp5_kms *mdp5_kms = platform_get_drvdata(pdev);
+   struct msm_drm_private *priv = platform_get_drvdata(pdev);
+   struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
  
  	DBG("");
  
@@ -966,7 +969,8 @@ static __maybe_unused int mdp5_runtime_suspend(struct device *dev)

  static __maybe_unused int mdp5_runtime_resume(struct device *dev)
  {
struct platform_device *pdev = to_platform_device(dev);
-   struct mdp5_kms *mdp5_kms = platform_get_drvdata(pdev);
+   struct msm_drm_private *priv = platform_get_drvdata(pdev);
+   struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
  
  	DBG("");
  


[PATCH] drm/msm/mdp5: fix kernel panic during shutdown

2022-09-09 Thread Fabien Parent
The kernel is panicking when rebooting on MSM8939:

# reboot -f
[   87.280853] Unable to handle kernel write to read-only memory at 
virtual address 88ed5810
...
snip
...
[   87.445142] Call trace:
[   87.452253]  mutex_lock+0x1c/0x50
[   87.454511]  msm_drv_shutdown+0x28/0x40
[   87.457984]  platform_shutdown+0x28/0x40
[   87.461629]  device_shutdown+0x14c/0x240
[   87.465796]  __do_sys_reboot+0x180/0x274
[   87.469703]  __arm64_sys_reboot+0x28/0x3c
[   87.473608]  invoke_syscall+0x54/0x124
[   87.477515]  el0_svc_common.constprop.0+0x44/0xec
[   87.481163]  do_el0_svc+0x90/0xe0
[   87.485934]  el0_svc+0x50/0xa4
[   87.489232]  el0t_64_sync_handler+0x11c/0x150
[   87.492185]  el0t_64_sync+0x190/0x194
[   87.496618] Code: f9800011 c85ffc03 ca010064 b564 (c8047c02)
[   87.500264] ---[ end trace  ]---
Segmentation fault

The issue comes from the fact that mdp5_init() is calling
platform_set_drvdata() and consequently overwriting the driver data
previously set by msm_drv_probe.
msm_drv_shutdown was casting the driver data as "struct msm_drm_private"
while it was actually a "struct mdp5_kms".

This commit fixes the issue by having mdp5_init() not override the
platform driver data, and instead use a series of
to_mdp5_kms(to_mdp_kms(priv->kms)) to retrieve the mdp5_kms from the
pdata.

Fixes: 54199009958f ("drm/msm: Fix shutdown")
Signed-off-by: Fabien Parent 
---
 drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c | 18 +++---
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c 
b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
index d2a48caf9d27..17aeabeedfeb 100644
--- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
+++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
@@ -634,7 +634,8 @@ static int mdp5_kms_init(struct drm_device *dev)
 
 static void mdp5_destroy(struct platform_device *pdev)
 {
-   struct mdp5_kms *mdp5_kms = platform_get_drvdata(pdev);
+   struct msm_drm_private *priv = platform_get_drvdata(pdev);
+   struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
int i;
 
if (mdp5_kms->ctlm)
@@ -797,7 +798,8 @@ static int mdp5_init(struct platform_device *pdev, struct 
drm_device *dev)
goto fail;
}
 
-   platform_set_drvdata(pdev, mdp5_kms);
+   /* set uninit-ed kms */
+   priv->kms = _kms->base.base;
 
spin_lock_init(_kms->resource_lock);
 
@@ -890,13 +892,13 @@ static int mdp5_init(struct platform_device *pdev, struct 
drm_device *dev)
if (ret)
goto fail;
 
-   /* set uninit-ed kms */
-   priv->kms = _kms->base.base;
-
return 0;
 fail:
if (mdp5_kms)
mdp5_destroy(pdev);
+
+   priv->kms = NULL;
+
return ret;
 }
 
@@ -956,7 +958,8 @@ static int mdp5_dev_remove(struct platform_device *pdev)
 static __maybe_unused int mdp5_runtime_suspend(struct device *dev)
 {
struct platform_device *pdev = to_platform_device(dev);
-   struct mdp5_kms *mdp5_kms = platform_get_drvdata(pdev);
+   struct msm_drm_private *priv = platform_get_drvdata(pdev);
+   struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
 
DBG("");
 
@@ -966,7 +969,8 @@ static __maybe_unused int mdp5_runtime_suspend(struct 
device *dev)
 static __maybe_unused int mdp5_runtime_resume(struct device *dev)
 {
struct platform_device *pdev = to_platform_device(dev);
-   struct mdp5_kms *mdp5_kms = platform_get_drvdata(pdev);
+   struct msm_drm_private *priv = platform_get_drvdata(pdev);
+   struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
 
DBG("");
 
-- 
2.37.2