From: Linus Torvalds <torvalds@osdl.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "David S. Miller" <davem@davemloft.net>,
linux-kernel@vger.kernel.org, greg@kroah.com,
helgehaf@aitel.hist.no
Subject: Re: Ignore disabled ROM resources at setup
Date: Mon, 29 Aug 2005 22:29:41 -0700 (PDT) [thread overview]
Message-ID: <Pine.LNX.4.58.0508292226580.3243@g5.osdl.org> (raw)
In-Reply-To: <1125377367.11948.54.camel@gaston>
On Tue, 30 Aug 2005, Benjamin Herrenschmidt wrote:
>
> I was just testing a slightly different one that appear to fix the
> problem :
...
> + rom_addr = region.start | (res->flags & PCI_REGION_FLAG_MASK);
I worry about this one. It's not really correct. The low en bits are
"reserved", and while I don't know whether writing zero is always correct,
I do know that just writing the low 4 bits with the old value is a bit
strange. And the flags don't save the other bits.
So I'd prefer either my previous diff, or one that just re-reads the bits
entirely, something like the appended..
What does the PCI spec say about the reserved bits? Do we have to save
them?
Linus
---
diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c
--- a/drivers/pci/rom.c
+++ b/drivers/pci/rom.c
@@ -24,9 +24,16 @@
static void pci_enable_rom(struct pci_dev *pdev)
{
u32 rom_addr;
+ struct resource *res = pdev->resource + PCI_ROM_RESOURCE;
+ struct pci_bus_region region;
+ if (!res->flags)
+ return;
+
+ pcibios_resource_to_bus(pdev, ®ion, res);
pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
- rom_addr |= PCI_ROM_ADDRESS_ENABLE;
+ rom_addr &= ~PCI_ROM_ADDRESS_MASK;
+ rom_addr |= region.start | PCI_ROM_ADDRESS_ENABLE;
pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr);
}
next prev parent reply other threads:[~2005-08-30 5:31 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <200508261859.j7QIxT0I016917@hera.kernel.org>
2005-08-30 2:38 ` Ignore disabled ROM resources at setup Benjamin Herrenschmidt
2005-08-30 3:15 ` Linus Torvalds
2005-08-30 4:47 ` Jon Smirl
2005-08-30 3:19 ` Benjamin Herrenschmidt
2005-08-30 3:52 ` Linus Torvalds
2005-08-30 4:09 ` Linus Torvalds
2005-08-30 4:20 ` David S. Miller
2005-08-30 4:37 ` Benjamin Herrenschmidt
2005-08-30 4:40 ` Linus Torvalds
2005-08-30 4:49 ` Benjamin Herrenschmidt
2005-08-30 5:29 ` Linus Torvalds [this message]
2005-08-30 6:46 ` Benjamin Herrenschmidt
2005-08-31 4:16 ` Benjamin Herrenschmidt
2005-08-30 4:51 ` Jon Smirl
2005-08-30 4:54 ` Benjamin Herrenschmidt
2005-08-30 5:15 ` Linus Torvalds
2005-08-30 14:39 ` Alan Cox
2005-08-30 15:29 ` Petr Vandrovec
2005-08-30 4:33 ` Benjamin Herrenschmidt
2005-08-30 5:03 ` Linus Torvalds
2005-08-30 6:40 ` Benjamin Herrenschmidt
2005-08-30 4:35 ` Jon Smirl
2005-08-30 5:32 ` David S. Miller
2005-08-30 6:43 ` Benjamin Herrenschmidt
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