[PATCH 2.6.15.3] alpha/pci: set cache line size for cards ignored by SRM

From: "Gabriele Gorla" <gorlik@penguintown.net>
To: ink@jurassic.park.msu.ru, rth@twiddle.net, gregkh@suse.de
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH 2.6.15.3] alpha/pci: set cache line size for cards ignored  by SRM
Date: Tue, 7 Feb 2006 14:54:43 -0800 (PST)	[thread overview]
Message-ID: <37389.10.0.0.8.1139352883.squirrel@mail> (raw)

From: Gabriele Gorla <gorlik@yahoo.com>

Set the cache line size in the PCI configuration space to a reasonable
value. SRM does not seem to set this register for the PCI cards that it
does not recognize. This makes drivers that expect cache line size to be
set by the card bios work on alpha.

Signed-off-by: Gabriele Gorla <gorlik@yahoo.com>

---

--- linux-2.6.15.3/arch/alpha/kernel/pci.c.orig 2006-02-07 14:24:59 -0800
+++ linux-2.6.15.3/arch/alpha/kernel/pci.c      2006-02-07 14:19:59 -0800
@@ -108,11 +108,24 @@ static void __init
 pcibios_fixup_final(struct pci_dev *dev)
 {
        unsigned int class = dev->class >> 8;
+       u8 cache_line_size;

        if (class == PCI_CLASS_BRIDGE_ISA || class ==
PCI_CLASS_BRIDGE_EISA) {
                dev->dma_mask = MAX_ISA_DMA_ADDRESS - 1;
                isa_bridge = dev;
        }
+
+       /* if the cache line is not set by SRM attempt to fix it */
+       pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cache_line_size);
+       if(cache_line_size == 0) {
+               pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE,
+                                     L1_CACHE_BYTES >> 2);
+               pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE,
+                                    &cache_line_size);
+               if(cache_line_size == (L1_CACHE_BYTES >> 2) )
+                       printk("PCI: Setting cache line size of device %s"
+                              " to %d\n", pci_name(dev), L1_CACHE_BYTES );
+       }
 }
 DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, pcibios_fixup_final);


