On 11/04/2015 02:13 PM, Jesse Barnes wrote:
On 11/04/2015 11:10 AM, Paulo Zanoni wrote:From our maintainer Daniel Vetter a few days ago: "Oh dear this is dead code. kdbg uses the fbcon, which always uses untiled, which means fbc will never be enabled. Also we have 0 users and 0 test coverage for kdbg on top of i915 (Jesse implemented it for fun years back). Imo just remove all this code." Adding to what Daniel said: for kgdboc's KMS support, intel_pipe_set_base_atomic() already manually disables FBC, so we won't do the in_dbg_master() check there. This is essentially a revert of: commit c924b934d0cd14a4559611da91f28f59acebe32a Author: Jason Wessel <jason.wessel@xxxxxxxxxxxxx> Date: Thu Aug 5 09:22:32 2010 -0500 i915: when kgdb is active display compression should be off Besides, it is not clear what is the exact problem caused by FBC, and why other features such as PSR, DRRS, IPS and RPM are not also checking for in_dbg_master(). IMHO we should either remove the code as suggested by Daniel or we add some nice comments explaining why is FBC so special. v2: Rebase due to new patch order. Cc: Jason Wessel <jason.wessel@xxxxxxxxxxxxx> Cc: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> --- drivers/gpu/drm/i915/intel_fbc.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c index 8e806be..e496cb0 100644 --- a/drivers/gpu/drm/i915/intel_fbc.c +++ b/drivers/gpu/drm/i915/intel_fbc.c @@ -890,12 +890,6 @@ static void __intel_fbc_update(struct drm_i915_private *dev_priv) goto out_disable; }- /* If the kernel debugger is active, always disable compression */- if (in_dbg_master()) { - set_no_fbc_reason(dev_priv, "Kernel debugger is active"); - goto out_disable; - } - /* WaFbcExceedCdClockThreshold:hsw,bdw */ if ((IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) && ilk_pipe_pixel_rate(crtc->config) >=Yeah looks fine. I haven't had any bug reports from the kdboc work, so I guess that means no one is using it. :) Reviewed-by: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
It was previously the case that the code here only got hit when you had a oops or a panic while running with the graphics console up. We would end up with fuzzy lines instead of a readable text console when we activated the atomic mode set. The kgdboc probably doesn't get used a whole lot but I have debugged a few strange WiFi and PM problems with it on a laptop and it worked well. :-) Cheers, Jason. _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
