Jan Weitzel <J.Weitzel@xxxxxxxxx> writes: > Am Dienstag, den 17.05.2011, 16:12 +0200 schrieb Kevin Hilman: >> Jan Weitzel <j.weitzel@xxxxxxxxx> writes: >> >> > omap4430 get i2c timeouts at each access after an NACK message. >> > OMAP_I2C_FLAG_RESET_REGS_POSTIDLE fix it. >> >> We need a little better changelog here. Specifically, *why* does this >> flag fix the problem? What exactly is going wrong such that this fix >> is needed. >> >> Does this happen all the time? only when off-mode is used? etc. > Yes all time. i2cdetect say "controller timed out" every two adresses. > >> Looking closer at how this flag is used in the driver, I think the >> driver's usage of runtime PM is a bit broken. I'm not sure if it's >> related to this problem, but I'll send a short series in a little bit to >> clean up the runtime PM usage, and get rid of the dev->idle flag which >> duplicates usage counting already provided by runtime PM. > In the isr OMAP_I2C_STAT_NACK set OMAP_I2C_CON_REG to OMAP_I2C_CON_STP, > clearing all other flags. Maybe this is wrong? > > On OMAP3 the OMAP_I2C_CON_REG flags are set again in the > OMAP_I2C_FLAG_RESET_REGS_POSTIDLE path of omap_i2c_unidle. > I am not sure if this is also the right place for OMAP4 Right, and I'm not sure either. That's why we need a better explanation/changelog about exactly what is happening and why this is the right fix. Kevin -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
