rapidio/tsi721: modify PCIe capability settings

Modify initialization of PCIe capability registers in Tsi721 mport driver:
 - change Completion Timeout value to avoid unexpected data transfer
   aborts during intensive traffic.
 - replace hardcoded offset of PCIe capability block by making it use the
   common function.

This patch is applicable to kernel versions starting from 3.2-rc1.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rapidio/devices/tsi721.c

@@ -2154,7 +2154,7 @@ static int __devinit tsi721_probe(struct pci_dev *pdev,
 				  const struct pci_device_id *id)
 {
 	struct tsi721_device *priv;
-	int i;
+	int i, cap;
 	int err;
 	u32 regval;
 
@@ -2262,10 +2262,20 @@ static int __devinit tsi721_probe(struct pci_dev *pdev,
 			dev_info(&pdev->dev, "Unable to set consistent DMA mask\n");
 	}
 
-	/* Clear "no snoop" and "relaxed ordering" bits. */
-	pci_read_config_dword(pdev, 0x40 + PCI_EXP_DEVCTL, &regval);
-	regval &= ~(PCI_EXP_DEVCTL_RELAX_EN | PCI_EXP_DEVCTL_NOSNOOP_EN);
-	pci_write_config_dword(pdev, 0x40 + PCI_EXP_DEVCTL, regval);
+	cap = pci_pcie_cap(pdev);
+	BUG_ON(cap == 0);
+
+	/* Clear "no snoop" and "relaxed ordering" bits, use default MRRS. */
+	pci_read_config_dword(pdev, cap + PCI_EXP_DEVCTL, &regval);
+	regval &= ~(PCI_EXP_DEVCTL_READRQ | PCI_EXP_DEVCTL_RELAX_EN |
+		    PCI_EXP_DEVCTL_NOSNOOP_EN);
+	regval |= 0x2 << MAX_READ_REQUEST_SZ_SHIFT;
+	pci_write_config_dword(pdev, cap + PCI_EXP_DEVCTL, regval);
+
+	/* Adjust PCIe completion timeout. */
+	pci_read_config_dword(pdev, cap + PCI_EXP_DEVCTL2, &regval);
+	regval &= ~(0x0f);
+	pci_write_config_dword(pdev, cap + PCI_EXP_DEVCTL2, regval | 0x2);
 
 	/*
 	 * FIXUP: correct offsets of MSI-X tables in the MSI-X Capability Block

drivers/rapidio/devices/tsi721.h

@@ -72,6 +72,8 @@
 #define TSI721_MSIXPBA_OFFSET	0x2a000
 #define TSI721_PCIECFG_EPCTL	0x400
 
+#define MAX_READ_REQUEST_SZ_SHIFT	12
+
 /*
  * Event Management Registers
  */