[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>

3 files changed, 46 insertions, 24 deletions

diff --git a/drivers/net/wireless/bcm43xx/bcm43xx_dma.c b/drivers/net/wireless/bcm43xx/bcm43xx_dma.c
index 76e3aed4b471..978ed099e285 100644
--- a/drivers/net/wireless/bcm43xx/bcm43xx_dma.c
+++ b/drivers/net/wireless/bcm43xx/bcm43xx_dma.c
@@ -705,11 +705,30 @@ int bcm43xx_dma_init(struct bcm43xx_private *bcm)
         struct bcm43xx_dmaring *ring;
         int err = -ENOMEM;
         int dma64 = 0;
-        u32 sbtmstatehi;
+        u64 mask = bcm43xx_get_supported_dma_mask(bcm);
+        int nobits;
 
-        sbtmstatehi = bcm43xx_read32(bcm, BCM43xx_CIR_SBTMSTATEHIGH);
-        if (sbtmstatehi & BCM43xx_SBTMSTATEHIGH_DMA64BIT)
+        if (mask == DMA_64BIT_MASK) {
                 dma64 = 1;
+                nobits = 64;
+        } else if (mask == DMA_32BIT_MASK)
+                nobits = 32;
+        else
+                nobits = 30;
+        err = pci_set_dma_mask(bcm->pci_dev, mask);
+        err |= pci_set_consistent_dma_mask(bcm->pci_dev, mask);
+        if (err) {
+#ifdef CONFIG_BCM43XX_PIO
+                printk(KERN_WARNING PFX "DMA not supported on this device."
+                                        " Falling back to PIO.\n");
+                bcm->__using_pio = 1;
+                return -ENOSYS;
+#else
+                printk(KERN_ERR PFX "FATAL: DMA not supported and PIO not configured. "
+                                    "Please recompile the driver with PIO support.\n");
+                return -ENODEV;
+#endif /* CONFIG_BCM43XX_PIO */
+        }
 
         /* setup TX DMA channels. */
         ring = bcm43xx_setup_dmaring(bcm, 0, 1, dma64);
@@ -755,8 +774,7 @@ int bcm43xx_dma_init(struct bcm43xx_private *bcm)
                 dma->rx_ring3 = ring;
         }
 
-        dprintk(KERN_INFO PFX "%s DMA initialized\n",
-                        dma64 ? "64-bit" : "32-bit");
+        dprintk(KERN_INFO PFX "%d-bit DMA initialized\n", nobits);
         err = 0;
 out:
         return err;
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 */
 
 
diff --git a/drivers/net/wireless/bcm43xx/bcm43xx_main.c b/drivers/net/wireless/bcm43xx/bcm43xx_main.c
index 7776b5c42ac7..a94c6d8826f8 100644
--- a/drivers/net/wireless/bcm43xx/bcm43xx_main.c
+++ b/drivers/net/wireless/bcm43xx/bcm43xx_main.c
@@ -2925,10 +2925,13 @@ static int bcm43xx_wireless_core_init(struct bcm43xx_private *bcm,
                 bcm43xx_write16(bcm, 0x043C, 0x000C);
 
         if (active_wlcore) {
-                if (bcm43xx_using_pio(bcm))
+                if (bcm43xx_using_pio(bcm)) {
                         err = bcm43xx_pio_init(bcm);
-                else
+                } else {
                         err = bcm43xx_dma_init(bcm);
+                        if (err == -ENOSYS)
+                                err = bcm43xx_pio_init(bcm);
+                }
                 if (err)
                         goto err_chip_cleanup;
         }
@@ -3992,8 +3995,6 @@ static int bcm43xx_init_private(struct bcm43xx_private *bcm,
                                 struct net_device *net_dev,
                                 struct pci_dev *pci_dev)
 {
-        int err;
-
         bcm43xx_set_status(bcm, BCM43xx_STAT_UNINIT);
         bcm->ieee = netdev_priv(net_dev);
         bcm->softmac = ieee80211_priv(net_dev);
@@ -4011,22 +4012,8 @@ static int bcm43xx_init_private(struct bcm43xx_private *bcm,
                      (void (*)(unsigned long))bcm43xx_interrupt_tasklet,
                      (unsigned long)bcm);
         tasklet_disable_nosync(&bcm->isr_tasklet);
-        if (modparam_pio) {
+        if (modparam_pio)
                 bcm->__using_pio = 1;
-        } else {
-                err = pci_set_dma_mask(pci_dev, DMA_30BIT_MASK);
-                err |= pci_set_consistent_dma_mask(pci_dev, DMA_30BIT_MASK);
-                if (err) {
-#ifdef CONFIG_BCM43XX_PIO
-                        printk(KERN_WARNING PFX "DMA not supported. Falling back to PIO.\n");
-                        bcm->__using_pio = 1;
-#else
-                        printk(KERN_ERR PFX "FATAL: DMA not supported and PIO not configured. "
-                                            "Recompile the driver with PIO support, please.\n");
-                        return -ENODEV;
-#endif /* CONFIG_BCM43XX_PIO */
-                }
-        }
         bcm->rts_threshold = BCM43xx_DEFAULT_RTS_THRESHOLD;
 
         /* default to sw encryption for now */