[PATCH v2] drm/amdgpu: fix that issue that the number of the crtc of the 3250c is not correct

[VURDIGERENATARAJ, CHANDAN]

>Hi Chandan,
>
>This issue we found on the Zork project which uses the kernel 5.4 on. So I just implemented it on kernel 5.4.
>For finding out which is 3250c, I referenced the function which is implemented from another function.
>Below is the part where I found it.
>
>drivers/gpu/drm/amd/amdgpu/amdgpu_device.c-
>	case CHIP_RAVEN:
>		if (adev->rev_id >= 8)
>			chip_name = "raven2";
>		else if (adev->pdev->device == 0x15d8)
>			chip_name = "picasso";
>		else
>			chip_name = "raven";
>		break;
>
>BR,
>Ryan Lin.

Suggest you to rebase to amd-staging-drm-next tip and update your changes accordingly and re-submit.

>
>Hi Ryan,
>
>Is this change applicable on a specific kernel version?
>On latest I see IP DISCOVERY based impl for CHIP_RAVEN.
>
>>[Why]
>>External displays take priority over internal display when there are fewer display controllers than displays.
>>
>> [How]
>>The root cause is because of that number of the crtc is not correct.
>>The number of the crtc on the 3250c is 3, but on the 3500c is 4.
>>On the source code, we can see that number of the crtc has been fixed at 4.
>>Needs to set the num_crtc to 3 for 3250c platform.
>>
>>v2:
>>   - remove unnecessary comments and Id
>>
>>Signed-off-by: Ryan Lin <tsung-hua.lin at amd.com>
>>
>>---
>> drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 12 +++++++++---
>> 1 file changed, 9 insertions(+), 3 deletions(-)
>>
>>diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>>index 40c91b448f7da..455a2c45e8cda 100644
>>--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>>+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>>@@ -2738,9 +2738,15 @@ static int dm_early_init(void *handle)
>> 		break;
>> #if defined(CONFIG_DRM_AMD_DC_DCN1_0)
>> 	case CHIP_RAVEN:
>>-		adev->mode_info.num_crtc = 4;
>>-		adev->mode_info.num_hpd = 4;
>>-		adev->mode_info.num_dig = 4;
>>+		if (adev->rev_id >= 8) {
>
>May I know what this ">=8" indicate? Also, should it be external_rev_id if its based on old version?
>
>>+			adev->mode_info.num_crtc = 3;
>>+			adev->mode_info.num_hpd = 3;
>>+			adev->mode_info.num_dig = 3;
>>+		} else {
>>+			adev->mode_info.num_crtc = 4;
>>+			adev->mode_info.num_hpd = 4;
>>+			adev->mode_info.num_dig = 4;
>>+		}
>> 		break;
>> #endif
>> #if defined(CONFIG_DRM_AMD_DC_DCN2_0)
>>--
>>2.25.1
>>
>
>BR,
>Chandan V N