On Wed, Mar 27, 2013 at 03:55:01PM +0100, Daniel Vetter wrote: > This fixes a regression introduced in > > commit e5868a318d1ae28f760f77bb91ce5deb751733fd > Author: Egbert Eich <eich at suse.de> > Date: Thu Feb 28 04:17:12 2013 -0500 > > DRM/i915: Convert HPD interrupts to make use of HPD pin assignment in encode > > Due to the irq setup rework in 3.9, see > > commit 20afbda209d708be66944907966486d0c1331cb8 > Author: Daniel Vetter <daniel.vetter at ffwll.ch> > Date: Tue Dec 11 14:05:07 2012 +0100 > > drm/i915: Fixup hpd irq register setup ordering > > Egbert Eich's hpd rework blows up on pch-split platforms - it walks > the encoder list before that has been set up completely. The new init > sequence is: > > 1. irq enabling > 2. modeset init > 3. hpd setup > > We need to move around the ibx setup a bit to fix this. > > Ville Syrj?l? pointed out in his review that we can't touch SDEIER > after the interrupt handler is set up, since that'll race with Paulo > Zanoni's PCH interrupt race fix: > > commit 44498aea293b37af1d463acd9658cdce1ecdf427 > Author: Paulo Zanoni <paulo.r.zanoni at intel.com> > Date: Fri Feb 22 17:05:28 2013 -0300 > > drm/i915: also disable south interrupts when handling them > > We fix that by unconditionally enabling all interrupts in SDEIER, but > masking them as-needed in SDEIMR. Since only the single-threaded > setup/teardown (or suspend/resume) code touches that, no further > locking is required. > > While at it also simplify the mask handling - we start out with all > interrupts cleared in the postinstall hook, and never enable a hpd > interrupt before hpd_irq_setup is called. > > And finally, for consistency rename the ibx hpd setup function to > ibx_hpd_irq_setup. > > v2: Fix race around SDEIER writes (Ville). > > v3: Remove the superflous posting read for SDEIER, spotted by Ville. > > Ville also wondered whether we shouldn't clear SDEIIR, since now > SDE interrupts are enabled before we have an irq handler installed. > But the master interrupt control bit in DEIER is still cleared, so we > should be fine. > > Cc: Egbert Eich <eich at suse.de> > Cc: Jesse Barnes <jbarnes at virtuousgeek.org> > Cc: Paulo Zanoni <paulo.r.zanoni at intel.com> > Cc: Ville Syrj?l? <ville.syrjala at linux.intel.com> > Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch> Makes sense to me. Reviewed-by: Ville Syrj?l? <ville.syrjala at linux.intel.com> <snip> -- Ville Syrj?l? Intel OTC
