diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 9caccd03dccb..51d142939a26 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -239,7 +239,6 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, uint32_t ch_data = ch_ctl + 4; int i; int recv_bytes; - uint32_t ctl; uint32_t status; uint32_t aux_clock_divider; int try, precharge; @@ -263,41 +262,43 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, else precharge = 5; + if (I915_READ(ch_ctl) & DP_AUX_CH_CTL_SEND_BUSY) { + DRM_ERROR("dp_aux_ch not started status 0x%08x\n", + I915_READ(ch_ctl)); + return -EBUSY; + } + /* Must try at least 3 times according to DP spec */ for (try = 0; try < 5; try++) { /* Load the send data into the aux channel data registers */ - for (i = 0; i < send_bytes; i += 4) { - uint32_t d = pack_aux(send + i, send_bytes - i); - - I915_WRITE(ch_data + i, d); - } - - ctl = (DP_AUX_CH_CTL_SEND_BUSY | - DP_AUX_CH_CTL_TIME_OUT_400us | - (send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) | - (precharge << DP_AUX_CH_CTL_PRECHARGE_2US_SHIFT) | - (aux_clock_divider << DP_AUX_CH_CTL_BIT_CLOCK_2X_SHIFT) | - DP_AUX_CH_CTL_DONE | - DP_AUX_CH_CTL_TIME_OUT_ERROR | - DP_AUX_CH_CTL_RECEIVE_ERROR); + for (i = 0; i < send_bytes; i += 4) + I915_WRITE(ch_data + i, + pack_aux(send + i, send_bytes - i)); /* Send the command and wait for it to complete */ - I915_WRITE(ch_ctl, ctl); - (void) I915_READ(ch_ctl); + I915_WRITE(ch_ctl, + DP_AUX_CH_CTL_SEND_BUSY | + DP_AUX_CH_CTL_TIME_OUT_400us | + (send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) | + (precharge << DP_AUX_CH_CTL_PRECHARGE_2US_SHIFT) | + (aux_clock_divider << DP_AUX_CH_CTL_BIT_CLOCK_2X_SHIFT) | + DP_AUX_CH_CTL_DONE | + DP_AUX_CH_CTL_TIME_OUT_ERROR | + DP_AUX_CH_CTL_RECEIVE_ERROR); for (;;) { - udelay(100); status = I915_READ(ch_ctl); if ((status & DP_AUX_CH_CTL_SEND_BUSY) == 0) break; + udelay(100); } /* Clear done status and any errors */ - I915_WRITE(ch_ctl, (status | - DP_AUX_CH_CTL_DONE | - DP_AUX_CH_CTL_TIME_OUT_ERROR | - DP_AUX_CH_CTL_RECEIVE_ERROR)); - (void) I915_READ(ch_ctl); - if ((status & DP_AUX_CH_CTL_TIME_OUT_ERROR) == 0) + I915_WRITE(ch_ctl, + status | + DP_AUX_CH_CTL_DONE | + DP_AUX_CH_CTL_TIME_OUT_ERROR | + DP_AUX_CH_CTL_RECEIVE_ERROR); + if (status & DP_AUX_CH_CTL_DONE) break; } @@ -324,15 +325,12 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, /* Unload any bytes sent back from the other side */ recv_bytes = ((status & DP_AUX_CH_CTL_MESSAGE_SIZE_MASK) >> DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT); - if (recv_bytes > recv_size) recv_bytes = recv_size; - for (i = 0; i < recv_bytes; i += 4) { - uint32_t d = I915_READ(ch_data + i); - - unpack_aux(d, recv + i, recv_bytes - i); - } + for (i = 0; i < recv_bytes; i += 4) + unpack_aux(I915_READ(ch_data + i), + recv + i, recv_bytes - i); return recv_bytes; }