| Message ID | 1342000071-25057-1-git-send-email-daniel.vetter@ffwll.ch (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, 11 Jul 2012 11:47:51 +0200, Daniel Vetter <daniel.vetter@ffwll.ch> wrote: > Somehow detect_ddc manages to fall through all checks when we think > that something responds on the ddc i2c address, but the edid read > failed. Fix this up by explicitly checking for this case. I'd prefer if we flatten the control flow in that function, state that the intention is to only return a definite positive result and if in any doubt we return false. Note that the ddc probe is implicit in drm_get_edid() and that we then have a stale comment about handling a broken EDID!. So intel_crtc_detect_ddc() { BUG_ON(crt->type != ANALOG); ret = false; if ((edid = drm_get_edid()) { ret = edid_is_analog(edid); kfree(edid); } return ret; } -Chris
diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c index 61d55d3..540561c 100644 --- a/drivers/gpu/drm/i915/intel_crt.c +++ b/drivers/gpu/drm/i915/intel_crt.c @@ -353,6 +353,9 @@ static bool intel_crt_detect_ddc(struct drm_connector *connector) is_digital = edid->input & DRM_EDID_INPUT_DIGITAL; connector->display_info.raw_edid = NULL; kfree(edid); + } else { + DRM_DEBUG_KMS("CRT not detected via DDC:0x50 [no valid EDID found]\n"); + return false; } if (!is_digital) {
Somehow detect_ddc manages to fall through all checks when we think that something responds on the ddc i2c address, but the edid read failed. Fix this up by explicitly checking for this case. This fixes a regression on newer chips because since commit aaa377302b2994fcc2c66741b47da33feb489dca Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Sat Jun 16 15:30:32 2012 +0200 drm/i915/crt: Do not rely upon the HPD presence pin we use ddc detection also on hotplug capable platforms. And one of these reads all 0s for any i2c transaction if nothing is connected to the vga port. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=51900 Tested-by: Yang Guang <guang.a.yang@intel.com> Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch> --- drivers/gpu/drm/i915/intel_crt.c | 3 +++ 1 file changed, 3 insertions(+)