The patch titled drivers/video/i810/i810-i2c.c: fix i2c bus handling has been added to the -mm tree. Its filename is drivers-video-i810-i810-i2cc-fix-i2c-bus-handling.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: drivers/video/i810/i810-i2c.c: fix i2c bus handling From: Stefani Seibold <stefani@xxxxxxxxxxx> Fix a longstanding bug in the i810 frame buffer driver. The handling of the i2c bus is wrong: A 1 bit should not written to the i2c, these will be done by switch the i2c to input. Driving an 1 bit active is against the i2c spec. An active driven of a 1 bit will result in very strange error, depending which side is the more powerful one. In my case it depends on the temperature of the Display-Controller-EEprom: With an cold eprom a got the correct EDID datas, with a warm one some of the 1 bits was 0 :-( The same bug is also in the intelfb driver in the file drivers/video/intelfb/intelfb_i2c.c. The functions intelfb_gpio_setscl() and intelfb_gpio_setsda() do drive the 1 bit active to the i2c bus. But since i have no card which is used by the intelfb driver i cannot fix it. Signed-off-by: Stefani Seibold <stefani@xxxxxxxxxxx> Cc: Paul Mundt <lethal@xxxxxxxxxxxx> Cc: Jean Delvare <khali@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/video/i810/i810-i2c.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff -puN drivers/video/i810/i810-i2c.c~drivers-video-i810-i810-i2cc-fix-i2c-bus-handling drivers/video/i810/i810-i2c.c --- a/drivers/video/i810/i810-i2c.c~drivers-video-i810-i810-i2cc-fix-i2c-bus-handling +++ a/drivers/video/i810/i810-i2c.c @@ -45,8 +45,10 @@ static void i810i2c_setscl(void *data, i struct i810fb_par *par = chan->par; u8 __iomem *mmio = par->mmio_start_virtual; - i810_writel(mmio, chan->ddc_base, (state ? SCL_VAL_OUT : 0) | SCL_DIR | - SCL_DIR_MASK | SCL_VAL_MASK); + if (state) + i810_writel(mmio, chan->ddc_base, SCL_DIR_MASK | SCL_VAL_MASK); + else + i810_writel(mmio, chan->ddc_base, SCL_DIR | SCL_DIR_MASK | SCL_VAL_MASK); i810_readl(mmio, chan->ddc_base); /* flush posted write */ } @@ -56,8 +58,10 @@ static void i810i2c_setsda(void *data, i struct i810fb_par *par = chan->par; u8 __iomem *mmio = par->mmio_start_virtual; - i810_writel(mmio, chan->ddc_base, (state ? SDA_VAL_OUT : 0) | SDA_DIR | - SDA_DIR_MASK | SDA_VAL_MASK); + if (state) + i810_writel(mmio, chan->ddc_base, SDA_DIR_MASK | SDA_VAL_MASK); + else + i810_writel(mmio, chan->ddc_base, SDA_DIR | SDA_DIR_MASK | SDA_VAL_MASK); i810_readl(mmio, chan->ddc_base); /* flush posted write */ } _ Patches currently in -mm which might be from stefani@xxxxxxxxxxx are drivers-video-i810-i810-i2cc-fix-i2c-bus-handling.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html