Re: [PATH] drm/loongson: add cleanup path for lsdc_ttm_init

[Icenowy Zheng <zhengxingda@iscas.ac.cn>]

在 2026-05-19二的 15:43 +0800，Xi Ruoyao写道：
> On Tue, 2026-05-19 at 15:41 +0800, yaolu@kylinos.cn wrote:
> > From: Lu Yao <yaolu@kylinos.cn>
> > 
> > There has resource leak when TTM_PL_VRAM or TTM_PL_TT man range
> > init
> > failed.
> > 
> > Signed-off-by: Lu Yao <yaolu@kylinos.cn>
> > ---
> >  drivers/gpu/drm/loongson/lsdc_ttm.c | 10 ++++++++--
> >  1 file changed, 8 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/loongson/lsdc_ttm.c
> > b/drivers/gpu/drm/loongson/lsdc_ttm.c
> > index d7441d96a0dc..c84bc582f77c 100644
> > --- a/drivers/gpu/drm/loongson/lsdc_ttm.c
> > +++ b/drivers/gpu/drm/loongson/lsdc_ttm.c
> > @@ -554,7 +554,7 @@ int lsdc_ttm_init(struct lsdc_device *ldev)
> >  
> >  	ret = ttm_range_man_init(&ldev->bdev, TTM_PL_VRAM, false,
> > num_vram_pages);
> >  	if (unlikely(ret))
> > -		return ret;
> > +		goto err_vram;
> >  
> >  	drm_info(ddev, "VRAM: %lu pages ready\n", num_vram_pages);
> >  
> > @@ -565,11 +565,17 @@ int lsdc_ttm_init(struct lsdc_device *ldev)
> >  
> >  	ret = ttm_range_man_init(&ldev->bdev, TTM_PL_TT, true,
> > num_gtt_pages);
> >  	if (unlikely(ret))
> > -		return ret;
> > +		goto err_gtt;
> >  
> >  	drm_info(ddev, "GTT: %lu pages ready\n", num_gtt_pages);
> >  
> >  	return drmm_add_action_or_reset(ddev, lsdc_ttm_fini,
> > ldev);
> 
> Isn't the error handling path also needed in case
> drmm_add_action_or_reset fails?

drmm_add_action_or_reset adds an action for teardown, and if it fails,
the teardown will immediately happen (this is what `or_reset` means).

The `lsdc_ttm_fini()` function will properly finalize both ttm range
managers and the ttm device, so it's not a problem here.

This patch is quite valid for handling the situation that some init
operations succeeded and some failed in this function.

Thanks,
Icenowy

> 
> > +
> > +err_gtt:
> > +	ttm_range_man_fini(&ldev->bdev, TTM_PL_VRAM);
> > +err_vram:
> > +	ttm_device_fini(&ldev->bdev);
> > +	return ret;
> >  }
> >  
> >  void lsdc_ttm_debugfs_init(struct lsdc_device *ldev)