Am 20.09.23 um 13:10 schrieb Thomas Zimmermann: [...]
if (!fi) @@ -619,6 +629,15 @@ static int ssd130x_primary_plane_helper_atomic_check(struct drm_plane *plane,pitch = drm_format_info_min_pitch(fi, 0, ssd130x->width); + if (new_plane_state->fb->format != fi) {+ void *buf; + + /* format conversion necessary; reserve buffer */ + buf = drm_xfrm_buf_reserve(&ssd130x->xfrm, pitch, GFP_KERNEL); + if (!buf) + return -ENOMEM; + }
Grrr! Right in the moment I sent this patch, I realized that this code would run concurrently with atomic_update. Hence, it cannot realloc the temporary buffer.
I think drivers could also pre-allocate in the device's probe function after calling drmm_xfrm_buf_init(). It's just enough memory for a single scanline.
+
ssd130x_state->buffer = kcalloc(pitch, ssd130x->height, GFP_KERNEL);
if (!ssd130x_state->buffer)
return -ENOMEM;
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstrasse 146, 90461 Nuernberg, Germany GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman HRB 36809 (AG Nuernberg)
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