lkml.org 
[lkml]   [2005]   [May]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] pci-sysfs: backport fix for 2.6.11.12
Greg, before 2.6.12, pci_write_config in pci-sysfs.c was broken, causing
incorrect data being written to the configuration register,
which in the case of my userspace driver results in system failure.

This has been fixed in 2.6.12-rc5:

http://www.kernel.org/diff/diffview.cgi?file=%2Fpub%2Flinux%2Fkernel%2Fv2.6%2Ftesting%2Fpatch-2.6.12-rc5.bz2;z=2656

Would you please consider merging the fix for 2.6.11.12 as well?

Alternatively (since there were multiple other changes in pci-sysfs.c), here's
a small patch to fix just this issue.

Thanks,
MST


cast from (signed) char to unsigned int in pci_write_config
causes the result to be sign extended, clobbering high bits in the result.
Thus:

# setpci -s 07:00.0 14.L=E4
# setpci -s 07:00.0 14.L
ffffffe4
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>

--- linux-2.6.11-openib/drivers/pci/pci-sysfs.c.bad 2005-05-30 13:45:02.000000000 +0300
+++ linux-2.6.11-openib/drivers/pci/pci-sysfs.c 2005-05-30 13:51:39.000000000 +0300
@@ -161,10 +161,10 @@ pci_write_config(struct kobject *kobj, c
}

while (size > 3) {
- unsigned int val = buf[off - init_off];
- val |= (unsigned int) buf[off - init_off + 1] << 8;
- val |= (unsigned int) buf[off - init_off + 2] << 16;
- val |= (unsigned int) buf[off - init_off + 3] << 24;
+ unsigned int val = (u8)buf[off - init_off];
+ val |= (unsigned int)(u8)buf[off - init_off + 1] << 8;
+ val |= (unsigned int)(u8)buf[off - init_off + 2] << 16;
+ val |= (unsigned int)(u8)buf[off - init_off + 3] << 24;
pci_write_config_dword(dev, off, val);
off += 4;
size -= 4;
--
MST - Michael S. Tsirkin
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-05-31 20:34    [from the cache]
©2003-2011 Jasper Spaans