diff options
authorNiclas Zeising <>2020-04-15 10:34:32 +0200
committerMichel Dänzer <>2020-05-27 15:36:44 +0000
commit680b9a2976f9eb8010c8160c425c2194fb5429d1 (patch)
parente923642bae6077f71a8f251fe885342757737224 (diff)
Fix return value check of drmIoctl()
When the drmModeSetCursor2() call was replaced with bare drmIoctl() call in b344e155, a bug was introduced. With the use of drmModeSetCursor2(), the return value from drmIoctl() (which calls ioctl()) were mangled, if they were negative, they were replaced by -errno by a wrapper function in xf86drMode.c in libdrm. After replacing drmModeSetCursor2() with the call to drmIoctl(), this mangling no longer happens, and we need to explicitly check if the call to drmIoctl() fails, which is indicated by returning -1, and then why it failed, by checking errno. If the error indicated by errno is EINVAL, then we can't use the DRM_IOCTL_MODE_CURSOR2 ioctl(), and need to fall back to the DRM_IOCTL_MODE_CURSOR ioctl(). This bug can manifest itself by an invisible hw cursor on systems where the DRM_IOCTL_MODE_CURSOR2 is not implemented by the graphics driver. Signed-off-by: Niclas Zeising <>
1 files changed, 1 insertions, 1 deletions
diff --git a/src/drmmode_display.c b/src/drmmode_display.c
index 1fcc252..09649dd 100644
--- a/src/drmmode_display.c
+++ b/src/drmmode_display.c
@@ -1784,7 +1784,7 @@ static void drmmode_show_cursor(xf86CrtcPtr crtc)
arg.hot_y = yhot;
ret = drmIoctl(pAMDGPUEnt->fd, DRM_IOCTL_MODE_CURSOR2, &arg);
- if (ret == -EINVAL)
+ if (ret == -1 && errno == EINVAL)
use_set_cursor2 = FALSE;