Hi Javier, On Fri, Jun 9, 2023 at 7:09 PM Javier Martinez Canillas <javierm@xxxxxxxxxx> wrote: > The resolutions for these panels are fixed and defined in the Device Tree, > so there's no point to allocate the buffers on each plane update and that > can just be done once. > > Let's do the allocation and free on the encoder enable and disable helpers > since that's where others initialization and teardown operations are done. > > Signed-off-by: Javier Martinez Canillas <javierm@xxxxxxxxxx> > Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx> > --- > > (no changes since v1) Thanks for your patch, which is now commit 49d7d581ceaf4cf8 ("drm/ssd130x: Don't allocate buffers on each plane update") in drm-misc/for-linux-next. > --- a/drivers/gpu/drm/solomon/ssd130x.c > +++ b/drivers/gpu/drm/solomon/ssd130x.c > @@ -701,14 +709,22 @@ static void ssd130x_encoder_helper_atomic_enable(struct drm_encoder *encoder, > return; > > ret = ssd130x_init(ssd130x); > - if (ret) { > - ssd130x_power_off(ssd130x); > - return; > - } > + if (ret) > + goto power_off; > + > + ret = ssd130x_buf_alloc(ssd130x); This appears to be too late, causing a NULL pointer dereference: [ 59.302761] [<c0303d90>] ssd130x_update_rect.isra.0+0x13c/0x340 [ 59.304231] [<c0304200>] ssd130x_primary_plane_helper_atomic_update+0x26c/0x284 [ 59.305716] [<c02f8d54>] drm_atomic_helper_commit_planes+0xfc/0x27c Bailing out from ssd130x_update_rect() when data_array is still NULL fixes that. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds