[lkml]   [2003]   [Aug]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH] i2c driver changes 2.6.0-test3
ChangeSet 1.1123.18.1, 2003/08/11 14:36:10-07:00,

[PATCH] I2C: Fix for i2c-piix4 with on some boards

Hello all. On some boards with an Intel PIIX4 the BIOS (such as the one
found on a Force CPCI-735) will incorrectly configure the chipset, and
leaves a register in an undefined state causing i2c to behave strangley.
The following patches (first vs lm_sensors-2.8.0 and then vs
2.6.0-test3) fixes the issue.

drivers/i2c/busses/i2c-piix4.c | 9 +++++++++
1 files changed, 9 insertions(+)

diff -Nru a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
--- a/drivers/i2c/busses/i2c-piix4.c Fri Aug 15 11:27:13 2003
+++ b/drivers/i2c/busses/i2c-piix4.c Fri Aug 15 11:27:13 2003
@@ -160,6 +160,15 @@

pci_read_config_byte(PIIX4_dev, SMBHSTCFG, &temp);
+ /* Some BIOS will set up the chipset incorrectly and leave a register
+ in an undefined state (causing I2C to act very strangely). */
+ if (temp & 0x02) {
+ printk("Fixed I2C problem on Force CPCI735\n");
+ temp = temp & 0xfd;
+ pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp);
+ }
/* If force_addr is set, we program the new address here. Just to make
sure, we disable the PIIX4 first. */
if (force_addr) {
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:47    [W:0.035 / U:1.228 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site