[PATCH 1/5] r8169: auto detect 32-bit slot

[Stephen Hemminger <shemminger@xxxxxxxx>]

Change driver to auto-detect when the board is in a 32-bit PCI slot and
avoid setting 64-bit dma mask. The module parameter method is no longer needed.

Signed-off-by: Stephen Hemminger <shemminger@xxxxxxxx>

diff -Nru a/drivers/net/r8169.c b/drivers/net/r8169.c
--- a/drivers/net/r8169.c       2005-03-09 11:23:58 -08:00
+++ b/drivers/net/r8169.c       2005-03-09 11:23:58 -08:00
@@ -182,7 +182,6 @@
 MODULE_DEVICE_TABLE(pci, rtl8169_pci_tbl);
 
 static int rx_copybreak = 200;
-static int use_dac;
 
 enum RTL8169_registers {
        MAC0 = 0,               /* Ethernet hardware address. */
@@ -419,8 +418,6 @@
 MODULE_DESCRIPTION("RealTek RTL-8169 Gigabit Ethernet driver");
 module_param_array(media, int, &num_media, 0);
 module_param(rx_copybreak, int, 0);
-module_param(use_dac, int, 0);
-MODULE_PARM_DESC(use_dac, "Enable PCI DAC. Unsafe on 32 bit PCI slot.");
 MODULE_LICENSE("GPL");
 MODULE_VERSION(RTL8169_VERSION);
 
@@ -1224,18 +1221,6 @@
 
        tp->cp_cmd = PCIMulRW | RxChkSum;
 
-       if ((sizeof(dma_addr_t) > 4) &&
-           !pci_set_dma_mask(pdev, DMA_64BIT_MASK) && use_dac) {
-               tp->cp_cmd |= PCIDAC;
-               dev->features |= NETIF_F_HIGHDMA;
-       } else {
-               rc = pci_set_dma_mask(pdev, DMA_32BIT_MASK);
-               if (rc < 0) {
-                       printk(KERN_ERR PFX "DMA configuration failed.\n");
-                       goto err_out_free_res;
-               }
-       }
-
        pci_set_master(pdev);
 
        /* ioremap MMIO region */
@@ -1278,6 +1263,19 @@
                i++;
        }
        tp->chipset = i;
+
+       if ((sizeof(dma_addr_t) > 4) &&
+           (RTL_R32(Config2) & (1<<3)) && 
+           !pci_set_dma_mask(pdev, DMA_64BIT_MASK)) {
+               tp->cp_cmd |= PCIDAC;
+               dev->features |= NETIF_F_HIGHDMA;
+       } else {
+               rc = pci_set_dma_mask(pdev, DMA_32BIT_MASK);
+               if (rc < 0) {
+                       printk(KERN_ERR PFX "DMA configuration failed.\n");
+                       goto err_out_free_res;
+               }
+       }
 
        *ioaddr_out = ioaddr;
        *dev_out = dev;