| Message ID | 20181003142458.33120-1-giulio.benetti@micronovasrl.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2,1/2] drm/sun4i: tcon: fix check of tcon->panel null pointer | expand |
Hi, On Wed, Oct 03, 2018 at 04:24:57PM +0200, Giulio Benetti 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. > > Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com> The commit log should be improved. The issue isn't really with the IS_ERR macro as you suggest, but that what is returned by of_drm_find_panel, and thus stored in tcon->panel. is not an error pointer in the first place but a NULL pointer on error. So the check doesn't check for the proper thing. Maxime
diff --git a/drivers/gpu/drm/sun4i/sun4i_lvds.c b/drivers/gpu/drm/sun4i/sun4i_lvds.c index af7dcb6da351..e7eb0d1e17be 100644 --- a/drivers/gpu/drm/sun4i/sun4i_lvds.c +++ b/drivers/gpu/drm/sun4i/sun4i_lvds.c @@ -75,7 +75,7 @@ static void sun4i_lvds_encoder_enable(struct drm_encoder *encoder) DRM_DEBUG_DRIVER("Enabling LVDS output\n"); - if (!IS_ERR(tcon->panel)) { + if (tcon->panel) { drm_panel_prepare(tcon->panel); drm_panel_enable(tcon->panel); } @@ -88,7 +88,7 @@ static void sun4i_lvds_encoder_disable(struct drm_encoder *encoder) DRM_DEBUG_DRIVER("Disabling LVDS output\n"); - if (!IS_ERR(tcon->panel)) { + if (tcon->panel) { drm_panel_disable(tcon->panel); drm_panel_unprepare(tcon->panel); } diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c index bf068da6b12e..f4a22689eb54 100644 --- a/drivers/gpu/drm/sun4i/sun4i_rgb.c +++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c @@ -135,7 +135,7 @@ static void sun4i_rgb_encoder_enable(struct drm_encoder *encoder) DRM_DEBUG_DRIVER("Enabling RGB output\n"); - if (!IS_ERR(tcon->panel)) { + if (tcon->panel) { drm_panel_prepare(tcon->panel); drm_panel_enable(tcon->panel); } @@ -148,7 +148,7 @@ static void sun4i_rgb_encoder_disable(struct drm_encoder *encoder) DRM_DEBUG_DRIVER("Disabling RGB output\n"); - if (!IS_ERR(tcon->panel)) { + if (tcon->panel) { drm_panel_disable(tcon->panel); drm_panel_unprepare(tcon->panel); } 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;
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. Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com> --- Changes V1->V2: * correct same bug for all same occurences in drm/sun4i folder drivers/gpu/drm/sun4i/sun4i_lvds.c | 4 ++-- drivers/gpu/drm/sun4i/sun4i_rgb.c | 4 ++-- drivers/gpu/drm/sun4i/sun4i_tcon.c | 2 +- 3 files changed, 5 insertions(+), 5 deletions(-)