[PATCH] bcm43xx: add DMA rx poll workaround to DMA4

Also add the Poll RX DMA Memory workaround to the DMA4
(xmitstatus) path.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 22 insertions, 9 deletions

diff --git a/drivers/net/wireless/bcm43xx/bcm43xx_dma.c b/drivers/net/wireless/bcm43xx/bcm43xx_dma.c
index bbecba02e697..d0318e525ba7 100644
--- a/drivers/net/wireless/bcm43xx/bcm43xx_dma.c
+++ b/drivers/net/wireless/bcm43xx/bcm43xx_dma.c
@@ -624,25 +624,28 @@ err_destroy_tx0:
 static u16 generate_cookie(struct bcm43xx_dmaring *ring,
                            int slot)
 {
-        u16 cookie = 0x0000;
+        u16 cookie = 0xF000;
 
         /* Use the upper 4 bits of the cookie as
          * DMA controller ID and store the slot number
-         * in the lower 12 bits
+         * in the lower 12 bits.
+         * Note that the cookie must never be 0, as this
+         * is a special value used in RX path.
          */
         switch (ring->mmio_base) {
         default:
                 assert(0);
         case BCM43xx_MMIO_DMA1_BASE:
+                cookie = 0xA000;
                 break;
         case BCM43xx_MMIO_DMA2_BASE:
-                cookie = 0x1000;
+                cookie = 0xB000;
                 break;
         case BCM43xx_MMIO_DMA3_BASE:
-                cookie = 0x2000;
+                cookie = 0xC000;
                 break;
         case BCM43xx_MMIO_DMA4_BASE:
-                cookie = 0x3000;
+                cookie = 0xD000;
                 break;
         }
         assert(((u16)slot & 0xF000) == 0x0000);
@@ -660,16 +663,16 @@ struct bcm43xx_dmaring * parse_cookie(struct bcm43xx_private *bcm,
         struct bcm43xx_dmaring *ring = NULL;
 
         switch (cookie & 0xF000) {
-        case 0x0000:
+        case 0xA000:
                 ring = dma->tx_ring0;
                 break;
-        case 0x1000:
+        case 0xB000:
                 ring = dma->tx_ring1;
                 break;
-        case 0x2000:
+        case 0xC000:
                 ring = dma->tx_ring2;
                 break;
-        case 0x3000:
+        case 0xD000:
                 ring = dma->tx_ring3;
                 break;
         default:
@@ -839,8 +842,18 @@ static void dma_rx(struct bcm43xx_dmaring *ring,
                 /* We received an xmit status. */
                 struct bcm43xx_hwxmitstatus *hw = (struct bcm43xx_hwxmitstatus *)skb->data;
                 struct bcm43xx_xmitstatus stat;
+                int i = 0;
 
                 stat.cookie = le16_to_cpu(hw->cookie);
+                while (stat.cookie == 0) {
+                        if (unlikely(++i >= 10000)) {
+                                assert(0);
+                                break;
+                        }
+                        udelay(2);
+                        barrier();
+                        stat.cookie = le16_to_cpu(hw->cookie);
+                }
                 stat.flags = hw->flags;
                 stat.cnt1 = hw->cnt1;
                 stat.cnt2 = hw->cnt2;