Re: [PATCH v1] drm/amdgpu: Fix ISP regression issue in kernel v7.0

["Nirujogi, Pratap" <pnirujog@amd.com>]

On 3/9/2026 5:58 PM, Mario Limonciello wrote:
> 
> 
> On 3/9/2026 4:50 PM, Pratap Nirujogi wrote:
>> Add NULL pointer checks for dev->type before accessing
>> dev->type->name in ISP genpd add/remove functions to
>> prevent kernel crashes. Also add MODULE_SOFTDEP to ensure
>> ISP driver dependencies are loaded in correct order.
>>
>> The regression was introduced in kernel v7.0 where MFD ISP
>> device enumeration doesn't complete by the time it is added
>> to gendp. The timing of ISP device enumeration has changed
>> because of the changes in registering the device sources in
>> the device hierarchy.
> 
> It's a little bit pedantic; but I /think/ there are two different 
> problems here with two different root causes that both happened in 7.0-rc.
> 
> As a consequence I think you should have this split out as two separate 
> patches in a series linked to a Fixes tag with the reason for each of them.
> 
sure, will split into 2 patches in the next version.


>>
>> Co-developed-by: Bin Du <Bin.Du@amd.com>
>> Fixes: 02c057ddefef ("ACPI: video: Convert the driver to a platform one")
>> Signed-off-by: Pratap Nirujogi <pratap.nirujogi@amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 1 +
>>   drivers/gpu/drm/amd/amdgpu/isp_v4_1_1.c | 4 ++--
>>   2 files changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/ 
>> drm/amd/amdgpu/amdgpu_drv.c
>> index 95d26f086d545..920595f0d22ca 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
>> @@ -3212,3 +3212,4 @@ module_exit(amdgpu_exit);
>>   MODULE_AUTHOR(DRIVER_AUTHOR);
>>   MODULE_DESCRIPTION(DRIVER_DESC);
>>   MODULE_LICENSE("GPL and additional rights");
>> +MODULE_SOFTDEP("post: amd_isp4_capture i2c-designware-amdisp pinctrl- 
>> amdisp");
>> \ No newline at end of file
>> diff --git a/drivers/gpu/drm/amd/amdgpu/isp_v4_1_1.c b/drivers/gpu/ 
>> drm/amd/amdgpu/isp_v4_1_1.c
>> index b3590b33cab9e..485ecdec96184 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/isp_v4_1_1.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/isp_v4_1_1.c
>> @@ -129,7 +129,7 @@ static int isp_genpd_add_device(struct device 
>> *dev, void *data)
>>       if (!pdev)
>>           return -EINVAL;
>> -    if (!dev->type->name) {
>> +    if (!dev->type || !dev->type->name) {
>>           drm_dbg(&adev->ddev, "Invalid device type to add\n");
>>           goto exit;
>>       }
>> @@ -165,7 +165,7 @@ static int isp_genpd_remove_device(struct device 
>> *dev, void *data)
>>       if (!pdev)
>>           return -EINVAL;
>> -    if (!dev->type->name) {
>> +    if (!dev->type || !dev->type->name) {
>>           drm_dbg(&adev->ddev, "Invalid device type to remove\n");
>>           goto exit;
>>       }
> 
>