On Sun, Aug 30, 2020 at 9:01 PM Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote: > > On Sun, Aug 30, 2020 at 3:23 PM Tali Perry <tali.perry1@xxxxxxxxx> wrote: > > > > > i2c: npcm7xx: bug fix timeout (usec instead of msec) > > This commit message is awful. Please read [1] as a tutorial how to > write a commit messages. > Would this be better: i2c: npcm7xx: Fix microsecond timeout calculation Inside npcm_i2c_master_xfer() we calculate a timeout for the entire transaction in microseconds, the calculation was wrong so big i2c massages would timeout before they ended. This commit fix that. > [1]: https://chris.beams.io/posts/git-commit/ > > ... > > > - /* Adaptive TimeOut: astimated time in usec + 100% margin */ > > - timeout_usec = (2 * 10000 / bus->bus_freq) * (2 + nread + nwrite); > > + /* > > + * Adaptive TimeOut: estimated time in usec + 100% margin: > > + * 2: double the timeout for clock stretching case > > + * 9: bits per transaction (including the ack/nack) > > > + * 1000000: micro second in a second > > No need. See below. > > > + */ > > > + timeout_usec = (2 * 9 * 1000000 / bus->bus_freq) * (2 + nread + nwrite); > > USEC_PER_SEC OK > > > timeout = max(msecs_to_jiffies(35), usecs_to_jiffies(timeout_usec)); > > if (nwrite >= 32 * 1024 || nread >= 32 * 1024) { > > dev_err(bus->dev, "i2c%d buffer too big\n", bus->num); > > -- > With Best Regards, > Andy Shevchenko -- Regards, Avi
