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| author | Dave Airlie <airlied@redhat.com> | 2012-05-29 14:09:06 +0400 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2012-05-29 14:09:06 +0400 |
| commit | a21f976094819d2862f8fdbd39ab5b22e7d27a1a (patch) | |
| tree | 67e2cb074ac4ccb46d1e9e0544e03c5ff58f891e /drivers/gpu/drm/i915/intel_i2c.c | |
| parent | 1ebf169ad4dc68f18cc0dab35163b0f324fc6c41 (diff) | |
| parent | ef12dab779acdb907eb4c3fa723e1c6f035ee13c (diff) | |
| download | linux-a21f976094819d2862f8fdbd39ab5b22e7d27a1a.tar.xz | |
Merge branch 'drm-intel-fixes' of git://people.freedesktop.org/~danvet/drm-intel into drm-fixes
* 'drm-intel-fixes' of git://people.freedesktop.org/~danvet/drm-intel:
drm/i915: tune down the noise of the RP irq limit fail
drm/i915: Remove the error message for unbinding pinned buffers
drm/i915: Limit page allocations to lowmem (dma32) for i965
drm/i915: always use RPNSWREQ for turbo change requests
drm/i915: reject doubleclocked cea modes on dp
drm/i915: Adding TV Out Missing modes.
drm/i915: wait for a vblank to pass after tv detect
drm/i915: no lvds quirk for HP t5740e Thin Client
drm/i915: enable vdd when switching off the eDP panel
drm/i915: Fix PCH PLL assertions to not assume CRTC:PLL relationship
drm/i915: Always update RPS interrupts thresholds along with frequency
drm/i915: properly handle interlaced bit for sdvo dtd conversion
drm/i915: fix module unload since error_state rework
drm/i915: be more careful when returning -ENXIO in gmbus transfer
Diffstat (limited to 'drivers/gpu/drm/i915/intel_i2c.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_i2c.c | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index 4a9707dd0f9c..1991a4408cf9 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -396,11 +396,22 @@ clear_err: * Wait for bus to IDLE before clearing NAK. * If we clear the NAK while bus is still active, then it will stay * active and the next transaction may fail. + * + * If no ACK is received during the address phase of a transaction, the + * adapter must report -ENXIO. It is not clear what to return if no ACK + * is received at other times. But we have to be careful to not return + * spurious -ENXIO because that will prevent i2c and drm edid functions + * from retrying. So return -ENXIO only when gmbus properly quiescents - + * timing out seems to happen when there _is_ a ddc chip present, but + * it's slow responding and only answers on the 2nd retry. */ + ret = -ENXIO; if (wait_for((I915_READ(GMBUS2 + reg_offset) & GMBUS_ACTIVE) == 0, - 10)) + 10)) { DRM_DEBUG_KMS("GMBUS [%s] timed out after NAK\n", adapter->name); + ret = -ETIMEDOUT; + } /* Toggle the Software Clear Interrupt bit. This has the effect * of resetting the GMBUS controller and so clearing the @@ -414,14 +425,6 @@ clear_err: adapter->name, msgs[i].addr, (msgs[i].flags & I2C_M_RD) ? 'r' : 'w', msgs[i].len); - /* - * If no ACK is received during the address phase of a transaction, - * the adapter must report -ENXIO. - * It is not clear what to return if no ACK is received at other times. - * So, we always return -ENXIO in all NAK cases, to ensure we send - * it at least during the one case that is specified. - */ - ret = -ENXIO; goto out; timeout: |