3.13 i915 brightness settings broken when going from docked -> undocked (original) (raw)

Jesse Barnes jbarnes at virtuousgeek.org
Mon Feb 24 08:15:22 PST 2014

On Sun, 23 Feb 2014 10:50:59 -0500 Josh Boyer <jwboyer at fedoraproject.org> wrote:

On Thu, Feb 20, 2014 at 07:31:41PM -0500, Josh Boyer wrote: >On Wed, Feb 19, 2014 at 9:20 PM, Josh Boyer <jwboyer at fedoraproject.org> wrote: >> Hi All, >> >> We've had a rather weird report[1] of the brightness adjustments being >> broken in a specific case with Thinkpad x220 hardware (SandyBridge >> based). If you boot the machine with it in a dock and then undock, >> the brightness adjustments do not work. That is with either the FN >> keys or the GNOME brightness slider. >> >> I can see that the value of >> /sys/class/backlight/acpivideo0/brightness increases/decreases but >> /sys/class/backlight/intelbacklight/brightness doesn't reflect any >> changes. With 3.12 this works, and oddly with 3.14-rc1 it works >> (specifically, it starts working around v3.13-10231-g53d8ab2 which is >> right after the first DRM merge for 3.14). With 3.13, if I undock and >> echo a higher value in the intelbacklightbrightness sysfs entry, the >> brightness will actually increase so it can be done manually, but it >> does not work as you'd expect. >> >> I'm in the middle of trying to do a reverse bisect for which patch >> fixes it in the 3.14-rcX series, but that's taking a while. I thought >> I'd email and see if anyone already knows about this situation, what >> patch in 3.13 broke this, and which one then fixed it again. Thus far >> all I've gathered is that backlight handling is confusing. > >The reverse bisect between 3.13 and 3.14-rc1 didn't prove fruitful, >either because I messed it up or there's a combination of things that >fix the issue. So instead I did a regular git bisect between 3.12 and >3.13 to see which commit broke things and caused the above behavior. > That landed me at: > >Author: Jesse Barnes <jbarnes at virtuousgeek.org> >Date: Thu Oct 31 18:55:49 2013 +0200 > > drm/i915: make backlight functions take a connector > >I have no idea if that makes sense or not, but it's at least something >that seems to be in a relevant area of code. Does anyone involved in >that know why it would cause the above symptoms on 3.13, and which >commit(s) fix it in 3.14-rc1?

Since nobody is replying I poked around a bit myself. The one commit that looks somewhat relevant in 3.14-rc1 seems to be: commit c91c9f32843a1b433de5a1ead4789a6bc8d3d914 Author: Jani Nikula <jani.nikula at intel.com> Date: Fri Nov 8 16:48:55 2013 +0200 drm/i915: make asle notifications update backlight on all connectors That doesn't apply cleanly on 3.13 because of the other reworks that went in first, so I came up with the patch below. It seems to fix it for my machine, but I'm waiting for confirmation from the original bug reporter still. Maybe this will elicit some comments? josh Backport of upstream commit c91c9f328 --- drivers/gpu/drm/i915/i915drv.h | 1 + drivers/gpu/drm/i915/intelopregion.c | 31 ++++++------------------------- drivers/gpu/drm/i915/intelpanel.c | 4 ++++ 3 files changed, 11 insertions(+), 25 deletions(-) diff --git a/drivers/gpu/drm/i915/i915drv.h b/drivers/gpu/drm/i915/i915drv.h index 221ac62..d6d4349 100644 --- a/drivers/gpu/drm/i915/i915drv.h +++ b/drivers/gpu/drm/i915/i915drv.h @@ -1371,6 +1371,7 @@ typedef struct drmi915private { /* backlight */ struct { + bool present; int level; bool enabled; spinlockt lock; /* bl registers and the above bl fields */ diff --git a/drivers/gpu/drm/i915/intelopregion.c b/drivers/gpu/drm/i915/intelopregion.c index 6d69a9b..b2a51ae 100644 --- a/drivers/gpu/drm/i915/intelopregion.c +++ b/drivers/gpu/drm/i915/intelopregion.c @@ -414,38 +414,19 @@ static u32 aslesetbacklight(struct drmdevice *dev, u32 bclp) return ASLCBACKLIGHTFAILED; mutexlock(&dev->modeconfig.mutex); - /* - * Could match the OpRegion connector here instead, but we'd also need - * to verify the connector could handle a backlight call. - */ - listforeachentry(encoder, &dev->modeconfig.encoderlist, head) - if (encoder->crtc == crtc) { - found = true; - break; - } - - if (!found) { - ret = ASLCBACKLIGHTFAILED; - goto out; - } - listforeachentry(connector, &dev->modeconfig.connectorlist, head) - if (connector->encoder == encoder) - intelconnector = tointelconnector(connector); - - if (!intelconnector) { - ret = ASLCBACKLIGHTFAILED; - goto out; + DRMDEBUGKMS("updating opregion backlight %d/255\n", bclp); + listforeachentry(connector, &dev->modeconfig.connectorlist, head) { + intelconnector = tointelconnector(connector); + if (devpriv->backlight.present) + intelpanelsetbacklight(intelconnector, bclp, 255); } - DRMDEBUGKMS("updating opregion backlight %d/255\n", bclp); - intelpanelsetbacklight(intelconnector, bclp, 255); iowrite32(DIVROUNDUP(bclp * 100, 255) | ASLECBLVVALID, &asle->cblv); -out: mutexunlock(&dev->modeconfig.mutex); - return ret; + return 0; } static u32 aslesetalsillum(struct drmdevice *dev, u32 alsi) diff --git a/drivers/gpu/drm/i915/intelpanel.c b/drivers/gpu/drm/i915/intelpanel.c index e6f782d..fa7b984 100644 --- a/drivers/gpu/drm/i915/intelpanel.c +++ b/drivers/gpu/drm/i915/intelpanel.c @@ -832,6 +832,9 @@ int intelpanelsetupbacklight(struct drmconnector *connector) devpriv->backlight.device = NULL; return -ENODEV; } + + devpriv->backlight.present = true; + return 0; } @@ -839,6 +842,7 @@ void intelpaneldestroybacklight(struct drmdevice *dev) { struct drmi915private *devpriv = dev->devprivate; if (devpriv->backlight.device) { + devpriv->backlight.present = false; backlightdeviceunregister(devpriv->backlight.device); devpriv->backlight.device = NULL; }

Yeah I think it looks reasonable, I was waiting for Jani to get back since I think he's thought about this more.

Fundamentally, mapping from an OpRegion connector to a drm connector is what we need, and your bits look a little closer to that than the current code.

-- Jesse Barnes, Intel Open Source Technology Center

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