On Tue, Jan 18, 2011 at 4:49 AM, Paul Walmsley <paul@xxxxxxxxx> wrote:
> On Mon, 17 Jan 2011, Santosh Shilimkar wrote:
>
>> The I2C timeout issue I could reproduce on my ES1.0 board. It's ES1.0
>> specific issue because I2C burst mode wasn't fuctional on it. Twl RTC
>> driver uses I2C burst mode and hence it times out. Other TWL I2C
>> module has no such issue.
>> The pull work-around we tried was not reliable hence it was dropped.
>>
>> In short the TWL RTC driver won't function on ES1.0. Apart from that
>> rest of the I2C clients should work as usual.
>
> Looks like the IRQ handling code uses it too:
>
> $ egrep -r 'twl_i2c_(write|read)\(' drivers/ | egrep -v twl-core | egrep -v 4030
> drivers/mfd/twl6030-irq.c: ret = twl_i2c_read(TWL_MODULE_PIH, sts.bytes,
> drivers/mfd/twl6030-irq.c: ret = twl_i2c_write(TWL_MODULE_PIH, sts.bytes,
> drivers/mfd/twl6030-irq.c: ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0],
> drivers/mfd/twl6030-irq.c: ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0],
> drivers/mfd/twl6030-irq.c: ret = twl_i2c_write(TWL_MODULE_PIH, &mask[0],
> drivers/rtc/rtc-twl.c: ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
> drivers/rtc/rtc-twl.c: ret = twl_i2c_write(TWL_MODULE_RTC, rtc_data,
> drivers/rtc/rtc-twl.c: ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
> drivers/rtc/rtc-twl.c: ret = twl_i2c_write(TWL_MODULE_RTC, alarm_data,
> $
>
> I'd assume this also would affect other, non-TWL, I2C endpoints, no?
>
in ES1, timeouts were observed only with RTC.
I2C burst access to IRQ registers and bq24156 were OK
> Sounds like a platform_data flag should be passed into the I2C driver code
> to indicate that burst transactions are buggy on OMAP4430ES1.
>
>
> - Paul
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