Eric Lee / smarc-ti-linux-kernel

5
Download as
Browse Code ยป

Commit 3ff04a160a891e56cdcee5c198d4c764d1c8c78b

Authored by Daniel Vetter
Committed by Jani Nikula
1 parent 0f9dc59db6
Exists in master and in 13 other branches dlt-processor-sdk-linux-03.00.00.04, processor-sdk-linux-02.00.01, smarc-ti-linux-3.15.y, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04, ti-linux-3.15.y, ti-lsk-linux-4.1.y

drm/i915: Don't WARN nor handle unexpected hpd interrupts on gmch platforms 

The status bits are unconditionally set, the control bits only enable
the actual interrupt generation. Which means if we get some random
other interrupts we'll bogusly complain about them.

So restrict the WARN to platforms with a sane hotplug interrupt
handling scheme. And even more important also don't attempt to process
the hpd bit since we've detected a storm already. Instead just clear
the bit silently.

This WARN has been introduced in

commit b8f102e8bf71cacf33326360fdf9dcfd1a63925b
Author: Egbert Eich <eich@suse.de>
Date:   Fri Jul 26 14:14:24 2013 +0200

    drm/i915: Add messages useful for HPD storm detection debugging (v2)

before that we silently handled the hpd event and so partially
defeated the storm detection.

v2: Pimp commit message (Jani)

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Egbert Eich <eich@suse.de>
Cc: bitlord <bitlord0xff@gmail.com>
Reported-by: bitlord <bitlord0xff@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Showing 1 changed file with 14 additions and 4 deletions Side-by-side Diff

drivers/gpu/drm/i915/i915_irq.c
Diff comments   View file @ 3ff04a1
... ... @@ -1362,10 +1362,20 @@
1362 1362 spin_lock(&dev_priv->irq_lock);
1363 1363 for (i = 1; i < HPD_NUM_PINS; i++) {
1364 1364  
1365   - WARN_ONCE(hpd[i] & hotplug_trigger &&
1366   - dev_priv->hpd_stats[i].hpd_mark == HPD_DISABLED,
1367   - "Received HPD interrupt (0x%08x) on pin %d (0x%08x) although disabled\n",
1368   - hotplug_trigger, i, hpd[i]);
  1365 + if (hpd[i] & hotplug_trigger &&
  1366 + dev_priv->hpd_stats[i].hpd_mark == HPD_DISABLED) {
  1367 + /*
  1368 + * On GMCH platforms the interrupt mask bits only
  1369 + * prevent irq generation, not the setting of the
  1370 + * hotplug bits itself. So only WARN about unexpected
  1371 + * interrupts on saner platforms.
  1372 + */
  1373 + WARN_ONCE(INTEL_INFO(dev)->gen >= 5 && !IS_VALLEYVIEW(dev),
  1374 + "Received HPD interrupt (0x%08x) on pin %d (0x%08x) although disabled\n",
  1375 + hotplug_trigger, i, hpd[i]);
  1376 +
  1377 + continue;
  1378 + }
1369 1379  
1370 1380 if (!(hpd[i] & hotplug_trigger) ||
1371 1381 dev_priv->hpd_stats[i].hpd_mark != HPD_ENABLED)