lkml.org 
[lkml]   [2012]   [Mar]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 06/10 v2] drm/i915/intel_i2c: return -ENXIO for device NAK
    Date
    Return -ENXIO if a device NAKs a transaction.

    Note: We should return -ETIMEDOUT, too if the transaction times out,
    however, that error path is currently handled by the 'bit-bang fallback'.

    Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
    ---
    drivers/gpu/drm/i915/intel_i2c.c | 12 +++++++++++-
    1 files changed, 11 insertions(+), 1 deletions(-)

    diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
    index 232b7cb..151b828 100644
    --- a/drivers/gpu/drm/i915/intel_i2c.c
    +++ b/drivers/gpu/drm/i915/intel_i2c.c
    @@ -242,6 +242,7 @@ gmbus_xfer(struct i2c_adapter *adapter,
    adapter);
    struct drm_i915_private *dev_priv = adapter->algo_data;
    int i, reg_offset;
    + int ret = 0;

    if (bus->force_bit)
    return intel_i2c_quirk_xfer(dev_priv,
    @@ -333,6 +334,15 @@ clear_err:
    I915_WRITE(GMBUS1 + reg_offset, GMBUS_SW_CLR_INT);
    I915_WRITE(GMBUS1 + reg_offset, 0);

    + /*
    + * 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;
    +
    done:
    /* Mark the GMBUS interface as disabled. We will re-enable it at the
    * start of the next xfer, till then let it sleep.
    @@ -341,7 +351,7 @@ done:

    mutex_unlock(&dev_priv->gmbus_mutex);

    - return i;
    + return ret ?: i;

    timeout:
    DRM_INFO("GMBUS timed out, falling back to bit banging on pin %d [%s]\n",
    --
    1.7.7.3


    \
     
     \ /
      Last update: 2012-03-09 19:51    [W:0.033 / U:30.784 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site