via: Make sure we flush write-combining using a follow-up read.

Signed-off-by: Dave Airlie <airlied@linux.ie>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/char/drm/via_dma.c b/drivers/char/drm/via_dma.c
index 7635e859b879..13a9c5ca4593 100644
--- a/drivers/char/drm/via_dma.c
+++ b/drivers/char/drm/via_dma.c
@@ -436,8 +436,10 @@ static int via_hook_segment(drm_via_private_t * dev_priv,
 
         paused = 0;
         via_flush_write_combine();
-        *dev_priv->last_pause_ptr = pause_addr_lo;
+        (void) *(volatile uint32_t *)(via_get_dma(dev_priv) -1);
+        *paused_at = pause_addr_lo;
         via_flush_write_combine();
+        (void) *paused_at;
         reader = *(dev_priv->hw_addr_ptr);
         ptr = ((volatile char *)paused_at - dev_priv->dma_ptr) +
                 dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr + 4;
@@ -536,7 +538,7 @@ static void via_cmdbuf_start(drm_via_private_t * dev_priv)
                           &pause_addr_hi, &pause_addr_lo, 1) - 1;
 
         via_flush_write_combine();
-        while(! *dev_priv->last_pause_ptr);
+        (void) *(volatile uint32_t *)dev_priv->last_pause_ptr;
 
         VIA_WRITE(VIA_REG_TRANSET, (HC_ParaType_PreCR << 16));
         VIA_WRITE(VIA_REG_TRANSPACE, command);