On Tue, Nov 06, 2012 at 11:27:29AM +1100, Stephen Rothwell wrote:
> Hi Bjorn,
>
> After merging the pci tree, today's linux-next build (x86_64 allmodconfig)
> failed like this:
> ...
> drivers/scsi/gdth.c: In function 'gdth_init_pci':
> drivers/scsi/gdth.c:1111:34: error: lvalue required as left operand of assignment
Here's what I think we should do about the GDT issue. I'll send this
via the usual channels.
commit c6156dd31228e608e0a820d2eed7403fd1fd620b
Author: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Date: Tue Nov 6 14:19:03 2012 -0700
[SCSI] gdth: Remove buggy ROM handling
The ROM address handling in gdth_init_pci() is useless and possibly
dangerous. This patch removes it.
"pci_resource_start(pdev, 8)" is not well-defined. PCI resources 0-5 are
standard PCI BARs and 6 is the expansion ROM. Resource 8 is either an
SR-IOV BAR (if CONFIG_PCI_IOV=y, resources 7-12 are SR-IOV BARs) or a
bridge window (resources 7-10).
The GDT device is neither an SR-IOV device nor a bridge, so in either case
resource 8 should be zero since struct pci_dev is allocated with kzalloc().
It is illegal for a driver to write an arbitrary address to the ROM BAR
because it has no way of knowing whether the ROM will conflict with another
device.
I think the only effect of the code being removed was to:
1) Enable the ROM at 0xFEFF0000 (possibly causing a conflict with
another device)
2) Delay one millisecond
3) Write zero to the ROM BAR, disabling it
I doubt the delay is needed, but I left it since it seems innocuous.
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
diff --git a/drivers/scsi/gdth.c b/drivers/scsi/gdth.c
index 5d72274..3efe4ef 100644
--- a/drivers/scsi/gdth.c
+++ b/drivers/scsi/gdth.c
@@ -1107,14 +1107,8 @@ static int __devinit gdth_init_pci(struct pci_dev *pdev, gdth_pci_str *pcistr,
pci_read_config_word(pdev, PCI_COMMAND, &command);
command |= 6;
pci_write_config_word(pdev, PCI_COMMAND, command);
- if (pci_resource_start(pdev, 8) == 1UL)
- pci_resource_start(pdev, 8) = 0UL;
- i = 0xFEFF0001UL;
- pci_write_config_dword(pdev, PCI_ROM_ADDRESS, i);
- gdth_delay(1);
- pci_write_config_dword(pdev, PCI_ROM_ADDRESS,
- pci_resource_start(pdev, 8));
-
+ gdth_delay(1);
+
dp6m_ptr = ha->brd;
/* Ensure that it is safe to access the non HW portions of DPMEM.
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