"Strashko, Grygorii" <[email protected]> writes: > Hi All, > > Sorry, for the late reply. > + CC Huzefa Kankroliwala - who is I2C driver owner on Android Kernel 3.4.
Hi Grygorii, thanks for reviewing. I was hoping you would have some ideas here as this was sounding familiar to something you had mentioned elsewhere. > Regarding this patch - from my point of view, it fixes corner case and not > an issue in general. > Let take a look on resume sequence: > - platform resume > - syscore resume > - resume_noirq > - enable IRQs - resume_device_irqs() > |- at this point IRQ handler will be invoked if IRQ state is > IRQS_PENDING. > |- so, the I2C device IRQ handler may be called at time when I2C adapter > IRQ is still disabled and, as result, the I2C device IRQ-handler may fail. > (I2C device and I2C adapter may use different physical IRQ lines) > - resume_late > |- enable I2C bus IRQ > > Possibly, the better way is to enable/disable I2C bus IRQ when needed - in > our case in omap_i2c_xfer(). > We use such approach in Android kernel 3.4 > (http://git.omapzoom.org/?p=kernel/omap.git;a=commitdiff;h=1445a4d3b587c164bd30d108b61760aaaa07365e) I agree, that should work and cover the cases where I2C is used by other processors also. Shubhrajyoti already posted something similar[1] but it needed some rework (comments from Russell and myself.) Huzefa, Shubhrajyoti, who can rework this idea for the upstream and/or follow up with the earlier patch[1]? Wolfram, I guess for now lets hold off on $SUBJECT patch. Seems we can come up with a broader solution. Thanks. Kevin [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2012-October/124427.html -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
