Re: [PATCH] drm/tegra: Remove existing framebuffer only if we support display

[Mikko Perttunen <cyndis@kapsi.fi>]

On 8/30/23 13:19, Thomas Zimmermann wrote:
> Hi
> 
> Am 25.08.23 um 15:22 schrieb Thierry Reding:
>> From: Thierry Reding <treding@nvidia.com>
>>
>> Tegra DRM doesn't support display on Tegra234 and later, so make sure
>> not to remove any existing framebuffers in that case.
>>
>> Signed-off-by: Thierry Reding <treding@nvidia.com>
>> ---
>>   drivers/gpu/drm/tegra/drm.c | 8 +++++---
>>   1 file changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
>> index b1e1a78e30c6..7a38dadbc264 100644
>> --- a/drivers/gpu/drm/tegra/drm.c
>> +++ b/drivers/gpu/drm/tegra/drm.c
>> @@ -1220,9 +1220,11 @@ static int host1x_drm_probe(struct 
>> host1x_device *dev)
>>       drm_mode_config_reset(drm);
>> -    err = drm_aperture_remove_framebuffers(&tegra_drm_driver);
>> -    if (err < 0)
>> -        goto hub;
>> +    if (drm->mode_config.num_crtc > 0) {
> 
> If you don't support the hardware, wouldn't it be better to return 
> -ENODEV if !num_crtc?

While display is not supported through TegraDRM on Tegra234+, certain 
multimedia accelerators are supported, so we need to finish probe for those.

Cheers,
Mikko

> 
> Best regards
> Thomas
> 
>> +        err = drm_aperture_remove_framebuffers(&tegra_drm_driver);
>> +        if (err < 0)
>> +            goto hub;
>> +    }
>>       err = drm_dev_register(drm, 0);
>>       if (err < 0)
>