[Cc'ing Kwangwoo via the alternate email address] * Dmitry Torokhov wrote: > On Mon, May 16, 2011 at 10:32:59AM +0200, Thierry Reding wrote: > > When the controller signals a pen-down event via the platform-specific > > GPIO, while the sample values indicate an invalid measurement, the > > measurement needs to be repeated. > > > > Would not we be interrupted again and take another sample then? Not necessarily. The problem is that if the pendown GPIO reports pendown, it doesn't necessarily mean that the pressure measurement will be valid. This is especially true if max_rt is configurable (as introduced by one of the follow-up patchs). What happens is that we are interrupted, check the GPIO to see that the pen is indeed down and then read the values and compute the pressure to see that it is invalid and we stop sampling. The TSC2007's nPEN_IRQ line never goes high again after that because the pen is still down (according to the GPIO). The comment in the old code of the (rt > max_rt) even says "[...] repeat at least once more the measurement", which the old code actually doesn't. Thierry
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