On Thu, Dec 18, 2003 at 10:26:40AM -0800, Greg KH wrote: > On Thu, Dec 18, 2003 at 11:16:12AM -0700, Tom Rini wrote: > > On Wed, Dec 17, 2003 at 03:52:50PM -0800, Greg KH wrote: > > > On Sat, Dec 06, 2003 at 10:10:27PM +0100, Jean Delvare wrote: > > > > Hi Greg, > > > > > > > > A few months ago, we added a workaround to i2c-piix4 to help it to work > > > > on a few boards. The fix was ported to 2.6, the patch is here: > > > > http://linuxusb.bkbits.net:8080/i2c-2.6/patch at 1.1123.21.1 > > > > > > > > It since turned out that it also breaks the module for other boards, and > > > > it even breaks more than it fixes (4 reports since lm_sensors-2.8.1 was > > > > released). The problem is under investigation by Tom Rini, the author of > > > > the original fix. > > > > > > > > I suggest that you reverse the fix in Linux 2.6 before 2.6.0 is > > > > released. Once we have enough information to submit a better one (could > > > > take some time), I'll send a new patch to you. > > > > > > Thanks, I've backed this patch out and will send it off to Linus. > > > > If it's not too late, how about doing the current work-around (module > > param to enable the fix) instead? > > Sure, got patch? :) Here you go: ===== drivers/i2c/busses/i2c-piix4.c 1.19 vs edited ===== --- 1.19/drivers/i2c/busses/i2c-piix4.c Mon Sep 22 09:02:10 2003 +++ edited/drivers/i2c/busses/i2c-piix4.c Fri Dec 19 09:40:03 2003 @@ -99,6 +99,13 @@ "Forcibly enable the PIIX4 at the given address. " "EXTREMELY DANGEROUS!"); +/* If fix_hstcfg is set to anything different from 0, we reset one of the + registers to be a valid value. */ +static int fix_hstcfg = 0; +MODULE_PARM(fix_hstcfg, "i"); +MODULE_PARM_DESC(fix_hstcfg, + "Fix config register. Needed on some boards (Force CPCI735)."); + static int piix4_transaction(void); @@ -164,9 +171,17 @@ /* 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) { - dev_info(&PIIX4_dev->dev, "Worked around buggy BIOS (I2C)\n"); - temp = temp & 0xfd; - pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp); + if (fix_hstcfg) { + dev_info(&PIIX4_dev->dev, "Working around buggy BIOS " + "(I2C)\n"); + temp &= 0xfd; + pci_write_config_byte(PIIX4_dev, SMBHSTCFG, temp); + } else { + dev_info(&PIIX4_dev->dev, "Unusual config register " + "value\n"); + dev_info(&PIIX4_dev->dev, "Try using fix_hstcfg=1 if " + "you experience problems\n"); + } } /* If force_addr is set, we program the new address here. Just to make -- Tom Rini http://gate.crashing.org/~trini/ -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 189 bytes Desc: Digital signature Url : http://lists.lm-sensors.org/pipermail/lm-sensors/attachments/20031219/4a2e5ede/attachment.bin
