The buf pointer was not being incremented inside the loop meaning the same block of data would be read or written repeatedly. Fixes: 09ac4fcb3f25 ("drm/ttm: Implement vm_operations_struct.access v2") Signed-off-by: Tom St Denis <tom.stdenis@xxxxxxx> Reviewed-by: Christian König <christian.koenig@xxxxxxx> (v2) Change 'buf' pointer to uint8_t* type --- drivers/gpu/drm/ttm/ttm_bo_vm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index 08a3c324242e..60fcef1593dd 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -316,7 +316,7 @@ static void ttm_bo_vm_close(struct vm_area_struct *vma) static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo, unsigned long offset, - void *buf, int len, int write) + uint8_t *buf, int len, int write) { unsigned long page = offset >> PAGE_SHIFT; unsigned long bytes_left = len; @@ -345,6 +345,7 @@ static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo, ttm_bo_kunmap(&map); page++; + buf += bytes; bytes_left -= bytes; offset = 0; } while (bytes_left); -- 2.14.3