Re: [PATCH 1/2] drm/pagemap Fix error paths in drm_pagemap_migrate_to_devmem

[Francois Dugast <francois.dugast@intel.com>]

On Wed, Jan 07, 2026 at 10:27:15AM -0800, Matthew Brost wrote:
> Avoid unlocking and putting device pages unless they were successfully
> locked, and do not calculate migrated_pages on error paths.
> 
> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> Fixes: 75af93b3f5d0 ("drm/pagemap, drm/xe: Support destination migration over interconnect")
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>

Reviewed-by: Francois Dugast <francois.dugast@intel.com>

> ---
>  drivers/gpu/drm/drm_pagemap.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c
> index ba099aa7c52f..aa43a8475100 100644
> --- a/drivers/gpu/drm/drm_pagemap.c
> +++ b/drivers/gpu/drm/drm_pagemap.c
> @@ -582,7 +582,7 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
>  
>  	err = ops->populate_devmem_pfn(devmem_allocation, npages, migrate.dst);
>  	if (err)
> -		goto err_finalize;
> +		goto err_aborted_migration;
>  
>  	own_pages = 0;
>  
> @@ -621,8 +621,10 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
>  		err = drm_pagemap_migrate_range(devmem_allocation, migrate.src, migrate.dst,
>  						pages, pagemap_addr, &last, &cur,
>  						mdetails);
> -		if (err)
> +		if (err) {
> +			npages = i + 1;
>  			goto err_finalize;
> +		}
>  	}
>  	cur.start = npages;
>  	cur.ops = NULL; /* Force migration */
> @@ -646,7 +648,7 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
>  err_aborted_migration:
>  	migrate_vma_pages(&migrate);
>  
> -	for (i = 0; i < npages;) {
> +	for (i = 0; !err && i < npages;) {
>  		struct page *page = migrate_pfn_to_page(migrate.src[i]);
>  		unsigned long nr_pages = page ? NR_PAGES(folio_order(page_folio(page))) : 1;
>  
> -- 
> 2.34.1
>