On Wed, Oct 3, 2018 at 5:59 AM Giulio Benetti
<giulio.benetti@xxxxxxxxxxxxxxxx> 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.