bcma: change max PCI read request size to 128

This PCIe controller does not support a max read request size above 128
bytes. The sold card I tested this controller with used 128 as default
value, but some new routers are sold with BCM4331 chips, which have a
default max read request size of 512. This device fails at the first
DMA reqeust whch is bigger than 126 bytes.

This patch changes the max read request size to 128 for every device on
the PCIe link.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/bcma/driver_pci_host.c b/drivers/bcma/driver_pci_host.c
index 30629a3d44cc..c3d7b03c2fdc 100644
--- a/drivers/bcma/driver_pci_host.c
+++ b/drivers/bcma/driver_pci_host.c
@@ -581,6 +581,7 @@ DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, bcma_core_pci_fixup_addresses);
 int bcma_core_pci_plat_dev_init(struct pci_dev *dev)
 {
         struct bcma_drv_pci_host *pc_host;
+        int readrq;
 
         if (dev->bus->ops->read != bcma_core_pci_hostmode_read_config) {
                 /* This is not a device on the PCI-core bridge. */
@@ -595,6 +596,11 @@ int bcma_core_pci_plat_dev_init(struct pci_dev *dev)
         dev->irq = bcma_core_irq(pc_host->pdev->core);
         pci_write_config_byte(dev, PCI_INTERRUPT_LINE, dev->irq);
 
+        readrq = pcie_get_readrq(dev);
+        if (readrq > 128) {
+                pr_info("change PCIe max read request size from %i to 128\n", readrq);
+                pcie_set_readrq(dev, 128);
+        }
         return 0;
 }
 EXPORT_SYMBOL(bcma_core_pci_plat_dev_init);