]> git.karo-electronics.de Git - karo-tx-linux.git/commitdiff
b43: Workaround DMA quirks
authorMichael Buesch <mb@bu3sch.de>
Thu, 24 Apr 2008 18:06:11 +0000 (20:06 +0200)
committerGreg Kroah-Hartman <gregkh@suse.de>
Thu, 1 May 2008 21:44:37 +0000 (14:44 -0700)
commit 1033b3ea11820ea1fb1b877207bd6724e9aaedc3 upstream

Some mainboards/CPUs don't allow DMA masks bigger than a certain limit.
Some VIA crap^h^h^h^hdevices have an upper limit of 0xFFFFFFFF. So in this
case a 64-bit b43 device would always fail to acquire the mask.
Implement a workaround to fallback to lower DMA mask, as we can always
also support a lower mask.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
drivers/net/wireless/b43/dma.c

index 48e912487b16f1bb82123c3f4289ac2a4153638f..4ec191556f237f7cdaf480e7441a0dbf5505561a 100644 (file)
@@ -822,6 +822,18 @@ static u64 supported_dma_mask(struct b43_wldev *dev)
        return DMA_30BIT_MASK;
 }
 
+static enum b43_dmatype dma_mask_to_engine_type(u64 dmamask)
+{
+       if (dmamask == DMA_30BIT_MASK)
+               return B43_DMA_30BIT;
+       if (dmamask == DMA_32BIT_MASK)
+               return B43_DMA_32BIT;
+       if (dmamask == DMA_64BIT_MASK)
+               return B43_DMA_64BIT;
+       B43_WARN_ON(1);
+       return B43_DMA_30BIT;
+}
+
 /* Main initialization function. */
 static
 struct b43_dmaring *b43_setup_dmaring(struct b43_wldev *dev,
@@ -982,6 +994,42 @@ void b43_dma_free(struct b43_wldev *dev)
        dma->tx_ring0 = NULL;
 }
 
+static int b43_dma_set_mask(struct b43_wldev *dev, u64 mask)
+{
+       u64 orig_mask = mask;
+       bool fallback = 0;
+       int err;
+
+       /* Try to set the DMA mask. If it fails, try falling back to a
+        * lower mask, as we can always also support a lower one. */
+       while (1) {
+               err = ssb_dma_set_mask(dev->dev, mask);
+               if (!err)
+                       break;
+               if (mask == DMA_64BIT_MASK) {
+                       mask = DMA_32BIT_MASK;
+                       fallback = 1;
+                       continue;
+               }
+               if (mask == DMA_32BIT_MASK) {
+                       mask = DMA_30BIT_MASK;
+                       fallback = 1;
+                       continue;
+               }
+               b43err(dev->wl, "The machine/kernel does not support "
+                      "the required %u-bit DMA mask\n",
+                      (unsigned int)dma_mask_to_engine_type(orig_mask));
+               return -EOPNOTSUPP;
+       }
+       if (fallback) {
+               b43info(dev->wl, "DMA mask fallback from %u-bit to %u-bit\n",
+                       (unsigned int)dma_mask_to_engine_type(orig_mask),
+                       (unsigned int)dma_mask_to_engine_type(mask));
+       }
+
+       return 0;
+}
+
 int b43_dma_init(struct b43_wldev *dev)
 {
        struct b43_dma *dma = &dev->dma;
@@ -991,27 +1039,10 @@ int b43_dma_init(struct b43_wldev *dev)
        enum b43_dmatype type;
 
        dmamask = supported_dma_mask(dev);
-       switch (dmamask) {
-       default:
-               B43_WARN_ON(1);
-       case DMA_30BIT_MASK:
-               type = B43_DMA_30BIT;
-               break;
-       case DMA_32BIT_MASK:
-               type = B43_DMA_32BIT;
-               break;
-       case DMA_64BIT_MASK:
-               type = B43_DMA_64BIT;
-               break;
-       }
-       err = ssb_dma_set_mask(dev->dev, dmamask);
-       if (err) {
-               b43err(dev->wl, "The machine/kernel does not support "
-                      "the required DMA mask (0x%08X%08X)\n",
-                      (unsigned int)((dmamask & 0xFFFFFFFF00000000ULL) >> 32),
-                      (unsigned int)(dmamask & 0x00000000FFFFFFFFULL));
-               return -EOPNOTSUPP;
-       }
+       type = dma_mask_to_engine_type(dmamask);
+       err = b43_dma_set_mask(dev, dmamask);
+       if (err)
+               return err;
 
        err = -ENOMEM;
        /* setup TX DMA channels. */