From: Tyrone Ting <warp5tw@gmail.com>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: avifishman70@gmail.com, tmaimon77@gmail.com,
tali.perry1@gmail.com, venture@google.com, yuenn@google.com,
benjaminfair@google.com, robh+dt@kernel.org, wsa@kernel.org,
krzysztof.kozlowski+dt@linaro.org, jarkko.nikula@linux.intel.com,
semen.protsenko@linaro.org, sven@svenpeter.dev, jsd@semihalf.com,
lukas.bulwahn@gmail.com, olof@lixom.net, arnd@arndb.de,
tali.perry@nuvoton.com, Avi.Fishman@nuvoton.com,
tomer.maimon@nuvoton.com, KWLIU@nuvoton.com, JJLIU0@nuvoton.com,
kfting@nuvoton.com, openbmc@lists.ozlabs.org,
linux-i2c@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 7/9] i2c: npcm: Handle spurious interrupts
Date: Wed, 11 May 2022 13:37:43 +0800 [thread overview]
Message-ID: <CACD3sJYPrQoWzOkOKM5tWuTWS0uEertBSrwMa5QmX0cMAPF4EQ@mail.gmail.com> (raw)
In-Reply-To: <Yno7IaBNnR5U2GuF@smile.fi.intel.com>
Hi Andy:
Thank you for your comments and they will be addressed.
Andy Shevchenko <andriy.shevchenko@linux.intel.com> 於 2022年5月10日 週二 下午6:15寫道:
>
> On Tue, May 10, 2022 at 05:16:52PM +0800, Tyrone Ting wrote:
> > From: Tali Perry <tali.perry1@gmail.com>
> >
> > On some platforms in rare cases (1 to 100,000 transactions),
> > the i2c gets a spurious interrupt which means that we enter an interrupt
> > but in the interrupt handler we don't find any status bit that points to
> > the reason we got this interrupt.
> >
> > This may be a case of a rare HW issue or signal integrity issue that is
> > still under investigation.
> >
> > In order to overcome this we are doing the following:
> > 1. Disable incoming interrupts in master mode only when slave mode is not
> > enabled.
> > 2. Clear end of busy (EOB) after every interrupt.
> > 3. Clear other status bits (just in case since we found them cleared)
> > 4. Return correct status during the interrupt that will finish the
> > transaction.
> >
> > On next xmit transaction if the bus is still busy the master will issue a
> > recovery process before issuing the new transaction.
>
> ...
>
> > + /* clear status bits for spurious interrupts */
>
> Clear
>
> ...
>
> > + /*
> > + * if irq is not one of the above, make sure EOB is disabled and all
>
> If
>
> > + * status bits are cleared.
> > + */
>
> ...
>
> > + /* verify no status bits are still set after bus is released */
>
> Verify
>
> ...
>
> > + /* check HW is OK: SDA and SCL should be high at this point. */
>
> Check
>
> ...
>
> > + if ((npcm_i2c_get_SDA(&bus->adap) == 0) ||
> > + (npcm_i2c_get_SCL(&bus->adap) == 0)) {
>
> This fits one line
>
> > + dev_err(bus->dev, "I2C%d init fail: lines are low", bus->num);
> > + dev_err(bus->dev, "SDA=%d SCL=%d", npcm_i2c_get_SDA(&bus->adap),
> > + npcm_i2c_get_SCL(&bus->adap));
>
> No '\n' at the end of each?!
>
> > + return -ENXIO;
> > + }
>
> ...
>
> > + /* clear status bits for spurious interrupts */
>
> Clear
>
> ...
>
> > + /* after any xfer, successful or not, stall and EOB must be disabled */
>
> After
>
> ...
>
> Maybe you chose the small letter for one-liner comments, but I see even in the
> original code the inconsistent style. Please, add an explanation to the cover
> letter and follow it, assuming you add the patch at the end of the series that
> makes comment style consistent (for the one-liners, for the multi-line comments
> we have a clear understanding about the style).
>
> --
> With Best Regards,
> Andy Shevchenko
>
>
Best Regards,
Tyrone
next prev parent reply other threads:[~2022-05-11 5:38 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-10 9:16 [PATCH v4 0/9] i2c: npcm: Bug fixes timeout, spurious interrupts Tyrone Ting
2022-05-10 9:16 ` [PATCH v4 1/9] dt-bindings: i2c: npcm: support NPCM845 Tyrone Ting
2022-05-11 15:24 ` Rob Herring
2022-05-12 1:31 ` Tyrone Ting
2022-05-13 8:26 ` Krzysztof Kozlowski
2022-05-10 9:16 ` [PATCH v4 2/9] i2c: npcm: Change the way of getting GCR regmap Tyrone Ting
2022-05-10 10:08 ` Andy Shevchenko
2022-05-11 1:34 ` Tyrone Ting
2022-05-16 19:48 ` Wolfram Sang
2022-05-17 1:05 ` Tyrone Ting
2022-05-17 6:04 ` Wolfram Sang
2022-05-17 6:09 ` Tyrone Ting
2022-05-10 9:16 ` [PATCH v4 3/9] i2c: npcm: Remove unused variable clk_regmap Tyrone Ting
2022-05-10 9:16 ` [PATCH v4 4/9] i2c: npcm: Fix timeout calculation Tyrone Ting
2022-05-10 9:16 ` [PATCH v4 5/9] i2c: npcm: Add tx complete counter Tyrone Ting
2022-05-10 9:16 ` [PATCH v4 6/9] i2c: npcm: Correct register access width Tyrone Ting
2022-05-10 9:16 ` [PATCH v4 7/9] i2c: npcm: Handle spurious interrupts Tyrone Ting
2022-05-10 10:14 ` Andy Shevchenko
2022-05-11 5:37 ` Tyrone Ting [this message]
2022-05-10 9:16 ` [PATCH v4 8/9] i2c: npcm: Remove own slave addresses 2:10 Tyrone Ting
2022-05-10 10:19 ` Andy Shevchenko
2022-05-11 1:39 ` Tyrone Ting
2022-05-16 1:23 ` Tyrone Ting
2022-05-10 9:16 ` [PATCH v4 9/9] i2c: npcm: Support NPCM845 Tyrone Ting
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