Message ID | 20200830122051.197892-1-tali.perry1@gmail.com |
---|---|
State | Not Applicable, archived |
Headers | show |
Series | [v2] i2c: npcm7xx: bug fix timeout (usec instead of msec) | expand |
On Sun, Aug 30, 2020 at 3:21 PM Tali Perry <tali.perry1@gmail.com> wrote: > > i2c: npcm7xx: bug fix timeout (usec instead of msec) > > Signed-off-by: Tali Perry <tali.perry1@gmail.com> Reviewed-by: Avi Fishman <avifishman70@gmail.com> > --- > drivers/i2c/busses/i2c-npcm7xx.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c > index 75f07138a6fa..abb334492a3d 100644 > --- a/drivers/i2c/busses/i2c-npcm7xx.c > +++ b/drivers/i2c/busses/i2c-npcm7xx.c > @@ -2093,8 +2093,13 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, > } > } > > - /* 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 > + */ > + timeout_usec = (2 * 9 * 1000000 / bus->bus_freq) * (2 + nread + nwrite); > 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); > > base-commit: d012a7190fc1fd72ed48911e77ca97ba4521bccd > -- > 2.22.0 > -- Regards, Avi
On Sun, Aug 30, 2020 at 3:23 PM Tali Perry <tali.perry1@gmail.com> 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. [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 > 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);
On Sun, Aug 30, 2020 at 9:01 PM Andy Shevchenko <andy.shevchenko@gmail.com> wrote: > > On Sun, Aug 30, 2020 at 3:23 PM Tali Perry <tali.perry1@gmail.com> 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
Please ignore my last mail, Tali already sent v3. On Mon, Aug 31, 2020 at 10:57 AM Avi Fishman <avifishman70@gmail.com> wrote: > > On Sun, Aug 30, 2020 at 9:01 PM Andy Shevchenko > <andy.shevchenko@gmail.com> wrote: > > > > On Sun, Aug 30, 2020 at 3:23 PM Tali Perry <tali.perry1@gmail.com> 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
diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c index 75f07138a6fa..abb334492a3d 100644 --- a/drivers/i2c/busses/i2c-npcm7xx.c +++ b/drivers/i2c/busses/i2c-npcm7xx.c @@ -2093,8 +2093,13 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, } } - /* 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 + */ + timeout_usec = (2 * 9 * 1000000 / bus->bus_freq) * (2 + nread + nwrite); 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);
i2c: npcm7xx: bug fix timeout (usec instead of msec) Signed-off-by: Tali Perry <tali.perry1@gmail.com> --- drivers/i2c/busses/i2c-npcm7xx.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) base-commit: d012a7190fc1fd72ed48911e77ca97ba4521bccd