[PATCH] bcm43xx-softmac: Fix system hang for x86-64 with >1GB RAM

The bcm43xx-softmac software currently fails when running on x86_64 systems
with more than 1GB RAM and one of the card variants with 30-bit DMA addressing.
This patch uses the address extension bits in the hardware to set the correct
DMA mask for the specific card in use.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/drivers/net/wireless/bcm43xx/bcm43xx_dma.h b/drivers/net/wireless/bcm43xx/bcm43xx_dma.h
index e04bcaddd1d0..ea16078cfe98 100644
--- a/drivers/net/wireless/bcm43xx/bcm43xx_dma.h
+++ b/drivers/net/wireless/bcm43xx/bcm43xx_dma.h
@@ -314,6 +314,23 @@ int bcm43xx_dma_tx(struct bcm43xx_private *bcm,
                    struct ieee80211_txb *txb);
 void bcm43xx_dma_rx(struct bcm43xx_dmaring *ring);
 
+/* Helper function that returns the dma mask for this device. */
+static inline
+u64 bcm43xx_get_supported_dma_mask(struct bcm43xx_private *bcm)
+{
+        int dma64 = bcm43xx_read32(bcm, BCM43xx_CIR_SBTMSTATEHIGH) &
+                                   BCM43xx_SBTMSTATEHIGH_DMA64BIT;
+        u16 mmio_base = bcm43xx_dmacontroller_base(dma64, 0);
+        u32 mask = BCM43xx_DMA32_TXADDREXT_MASK;
+
+        if (dma64)
+                return DMA_64BIT_MASK;
+        bcm43xx_write32(bcm, mmio_base + BCM43xx_DMA32_TXCTL, mask);
+        if (bcm43xx_read32(bcm, mmio_base + BCM43xx_DMA32_TXCTL) & mask)
+                return DMA_32BIT_MASK;
+        return DMA_30BIT_MASK;
+}
+
 #else /* CONFIG_BCM43XX_DMA */