From 755528c860b05fcecda1c88a2bdaffcb50760a7f Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@g5.osdl.org>
Date: Fri, 26 Aug 2005 10:49:22 -0700
Subject: [PATCH] Ignore disabled ROM resources at setup
Writing even a disabled value seems to mess up some matrox graphics
cards. It may be a card-related issue, but we may also be writing
reserved low bits in the result.
This was a fall-out of switching x86 over to the generic PCI resource
allocation code, and needs more debugging. In particular, the old x86
code defaulted to not doing any resource allocations at all for ROM
resources.
In the meantime, this has been reported to make X happier by Helge
Hafting <helgehaf@aitel.hist.no>.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
drivers/pci/setup-res.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 84eedc965688d..5598b4714f77a 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -53,7 +53,9 @@ pci_update_resource(struct pci_dev *dev, struct resource *res, int resno)
if (resno < 6) {
reg = PCI_BASE_ADDRESS_0 + 4 * resno;
} else if (resno == PCI_ROM_RESOURCE) {
- new |= res->flags & IORESOURCE_ROM_ENABLE;
+ if (!(res->flags & IORESOURCE_ROM_ENABLE))
+ return;
+ new |= PCI_ROM_ADDRESS_ENABLE;
reg = dev->rom_base_reg;
} else {
/* Hmm, non-standard resource. */
--
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