Messages in this thread Patch in this message |  | | From | Chen-Yu Tsai <> | Date | Wed, 3 Oct 2018 17:43:09 +0800 | Subject | Re: [PATCH 1/2] drm/sun4i: tcon: fix check of tcon->panel null pointer |
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On Wed, Oct 3, 2018 at 5:59 AM Giulio Benetti <giulio.benetti@micronovasrl.com> wrote: > > At the moment, the check of tcon->panel to be valid is wrong. IS_ERR() > has been used, but that macro doesn't check if tcon->panel pointer is > null or not, but check if tcon->panel is between -1 and -4095(MAX_ERRNO). > > Remove IS_ERR() from tcon->panel checking and let "if (tcon->panel)" as > condition to check if it's a pointer not null.
There's actually more than one occurance of this error:
drivers/gpu/drm/sun4i/sun4i_lvds.c: if (!IS_ERR(tcon->panel)) { drivers/gpu/drm/sun4i/sun4i_lvds.c: if (!IS_ERR(tcon->panel)) { drivers/gpu/drm/sun4i/sun4i_rgb.c: if (!IS_ERR(tcon->panel)) { drivers/gpu/drm/sun4i/sun4i_rgb.c: if (!IS_ERR(tcon->panel)) {
These four are responsible for enabling and disabling the panel.
drivers/gpu/drm/sun4i/sun4i_tcon.c: if (!IS_ERR(tcon->panel)) {
All this looks like it was left over from commit ebc9446135671 ("drm: convert drivers to use drm_of_find_panel_or_bridge"). We have checks against tcon->panel in several places and not all of them were converted.
ChenYu
> Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com> > --- > drivers/gpu/drm/sun4i/sun4i_tcon.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c > index c78cd35a1294..e4b3bd0307ef 100644 > --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c > +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c > @@ -555,7 +555,7 @@ static void sun4i_tcon0_mode_set_rgb(struct sun4i_tcon *tcon, > * Following code is a way to avoid quirks all around TCON > * and DOTCLOCK drivers. > */ > - if (!IS_ERR(tcon->panel)) { > + if (tcon->panel) { > struct drm_panel *panel = tcon->panel; > struct drm_connector *connector = panel->connector; > struct drm_display_info display_info = connector->display_info; > -- > 2.17.1 >
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