From: Andy Shevchenko <andriy.shevchenko@linux.intel.com> To: Tyrone Ting <warp5tw@gmail.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, krzysztof.kozlowski@canonical.com, wsa@kernel.org, jarkko.nikula@linux.intel.com, semen.protsenko@linaro.org, sven@svenpeter.dev, jie.deng@intel.com, 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: Tue, 10 May 2022 13:14:57 +0300 [thread overview] Message-ID: <Yno7IaBNnR5U2GuF@smile.fi.intel.com> (raw) In-Reply-To: <20220510091654.8498-8-warp5tw@gmail.com> 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
WARNING: multiple messages have this Message-ID (diff)
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com> To: Tyrone Ting <warp5tw@gmail.com> Cc: tmaimon77@gmail.com, devicetree@vger.kernel.org, tali.perry1@gmail.com, jsd@semihalf.com, benjaminfair@google.com, krzysztof.kozlowski@canonical.com, openbmc@lists.ozlabs.org, JJLIU0@nuvoton.com, lukas.bulwahn@gmail.com, tomer.maimon@nuvoton.com, KWLIU@nuvoton.com, arnd@arndb.de, sven@svenpeter.dev, robh+dt@kernel.org, Avi.Fishman@nuvoton.com, semen.protsenko@linaro.org, jie.deng@intel.com, avifishman70@gmail.com, venture@google.com, linux-kernel@vger.kernel.org, wsa@kernel.org, kfting@nuvoton.com, tali.perry@nuvoton.com, jarkko.nikula@linux.intel.com, olof@lixom.net, linux-i2c@vger.kernel.org Subject: Re: [PATCH v4 7/9] i2c: npcm: Handle spurious interrupts Date: Tue, 10 May 2022 13:14:57 +0300 [thread overview] Message-ID: <Yno7IaBNnR5U2GuF@smile.fi.intel.com> (raw) In-Reply-To: <20220510091654.8498-8-warp5tw@gmail.com> 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
next prev parent reply other threads:[~2022-05-10 10:15 UTC|newest] Thread overview: 46+ 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 ` Tyrone Ting 2022-05-10 9:16 ` [PATCH v4 1/9] dt-bindings: i2c: npcm: support NPCM845 Tyrone Ting 2022-05-10 9:16 ` Tyrone Ting 2022-05-11 15:24 ` Rob Herring 2022-05-11 15:24 ` Rob Herring 2022-05-12 1:31 ` Tyrone Ting 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 9:16 ` Tyrone Ting 2022-05-10 10:08 ` Andy Shevchenko 2022-05-10 10:08 ` Andy Shevchenko 2022-05-11 1:34 ` Tyrone Ting 2022-05-11 1:34 ` Tyrone Ting 2022-05-16 19:48 ` Wolfram Sang 2022-05-16 19:48 ` Wolfram Sang 2022-05-17 1:05 ` Tyrone Ting 2022-05-17 1:05 ` Tyrone Ting 2022-05-17 6:04 ` Wolfram Sang 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 ` Tyrone Ting 2022-05-10 9:16 ` [PATCH v4 4/9] i2c: npcm: Fix timeout calculation Tyrone Ting 2022-05-10 9:16 ` Tyrone Ting 2022-05-10 9:16 ` [PATCH v4 5/9] i2c: npcm: Add tx complete counter Tyrone Ting 2022-05-10 9:16 ` Tyrone Ting 2022-05-10 9:16 ` [PATCH v4 6/9] i2c: npcm: Correct register access width Tyrone Ting 2022-05-10 9:16 ` Tyrone Ting 2022-05-10 9:16 ` [PATCH v4 7/9] i2c: npcm: Handle spurious interrupts Tyrone Ting 2022-05-10 9:16 ` Tyrone Ting 2022-05-10 10:14 ` Andy Shevchenko [this message] 2022-05-10 10:14 ` Andy Shevchenko 2022-05-11 5:37 ` Tyrone Ting 2022-05-11 5:37 ` Tyrone Ting 2022-05-10 9:16 ` [PATCH v4 8/9] i2c: npcm: Remove own slave addresses 2:10 Tyrone Ting 2022-05-10 9:16 ` Tyrone Ting 2022-05-10 10:19 ` Andy Shevchenko 2022-05-10 10:19 ` Andy Shevchenko 2022-05-11 1:39 ` Tyrone Ting 2022-05-11 1:39 ` Tyrone Ting 2022-05-16 1:23 ` Tyrone Ting 2022-05-16 1:23 ` Tyrone Ting 2022-05-10 9:16 ` [PATCH v4 9/9] i2c: npcm: Support NPCM845 Tyrone Ting 2022-05-10 9:16 ` Tyrone Ting
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=Yno7IaBNnR5U2GuF@smile.fi.intel.com \ --to=andriy.shevchenko@linux.intel.com \ --cc=Avi.Fishman@nuvoton.com \ --cc=JJLIU0@nuvoton.com \ --cc=KWLIU@nuvoton.com \ --cc=arnd@arndb.de \ --cc=avifishman70@gmail.com \ --cc=benjaminfair@google.com \ --cc=devicetree@vger.kernel.org \ --cc=jarkko.nikula@linux.intel.com \ --cc=jie.deng@intel.com \ --cc=jsd@semihalf.com \ --cc=kfting@nuvoton.com \ --cc=krzysztof.kozlowski@canonical.com \ --cc=linux-i2c@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=lukas.bulwahn@gmail.com \ --cc=olof@lixom.net \ --cc=openbmc@lists.ozlabs.org \ --cc=robh+dt@kernel.org \ --cc=semen.protsenko@linaro.org \ --cc=sven@svenpeter.dev \ --cc=tali.perry1@gmail.com \ --cc=tali.perry@nuvoton.com \ --cc=tmaimon77@gmail.com \ --cc=tomer.maimon@nuvoton.com \ --cc=venture@google.com \ --cc=warp5tw@gmail.com \ --cc=wsa@kernel.org \ --cc=yuenn@google.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.