> -----Original Message----- > From: Joel Stanley <[email protected]> > Sent: Thursday, May 20, 2021 7:29 AM > To: Quan Nguyen <[email protected]>; Ryan Chen > <[email protected]> > Cc: Corey Minyard <[email protected]>; Rob Herring <[email protected]>; > Andrew Jeffery <[email protected]>; Brendan Higgins > <[email protected]>; Benjamin Herrenschmidt > <[email protected]>; Wolfram Sang <[email protected]>; Philipp Zabel > <[email protected]>; [email protected]; > devicetree <[email protected]>; Linux ARM > <[email protected]>; linux-aspeed > <[email protected]>; Linux Kernel Mailing List > <[email protected]>; [email protected]; Open Source > Submission <[email protected]>; Phong Vo > <[email protected]>; Thang Q . Nguyen > <[email protected]>; OpenBMC Maillist > <[email protected]> > Subject: Re: [PATCH v3 3/7] i2c: aspeed: Fix unhandled Tx done with NAK > > Ryan, can you please review this change? > > On Wed, 19 May 2021 at 07:50, Quan Nguyen > <[email protected]> wrote: > > > > It is observed that in normal condition, when the last byte sent by > > slave, the Tx Done with NAK irq will raise. > > But it is also observed that sometimes master issues next transaction > > too quick while the slave irq handler is not yet invoked and Tx Done > > with NAK irq of last byte of previous READ PROCESSED was not ack'ed. > > This Tx Done with NAK irq is raised together with the Slave Match and > > Rx Done irq of the next coming transaction from master. > > Unfortunately, the current slave irq handler handles the Slave Match > > and Rx Done only in higher priority and ignore the Tx Done with NAK, > > causing the complain as below: > > "aspeed-i2c-bus 1e78a040.i2c-bus: irq handled != irq. expected > > 0x00000086, but was 0x00000084" > > > > This commit handles this case by emitting a Slave Stop event for the > > Tx Done with NAK before processing Slave Match and Rx Done for the > > coming transaction from master. > > It sounds like this patch is independent of the rest of the series, and can > go in > on it's own. Please send it separately to the i2c maintainers and add a > suitable > Fixes line, such as: > > Fixes: f9eb91350bb2 ("i2c: aspeed: added slave support for Aspeed I2C > driver") > > > > > Signed-off-by: Quan Nguyen <[email protected]> > > --- > > v3: > > + First introduce in v3 [Quan] > > > > drivers/i2c/busses/i2c-aspeed.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/drivers/i2c/busses/i2c-aspeed.c > > b/drivers/i2c/busses/i2c-aspeed.c index 724bf30600d6..3fb37c3f23d4 > > 100644 > > --- a/drivers/i2c/busses/i2c-aspeed.c > > +++ b/drivers/i2c/busses/i2c-aspeed.c > > @@ -254,6 +254,11 @@ static u32 aspeed_i2c_slave_irq(struct > > aspeed_i2c_bus *bus, u32 irq_status) > > > > /* Slave was requested, restart state machine. */ > > if (irq_status & ASPEED_I2CD_INTR_SLAVE_MATCH) { > > Can you explain why you need to do this handing inside the SLAVE_MATCH > case? > > Could you instead move the TX_NAK handling to be above the SLAVE_MATCH > case? > > > + if (irq_status & ASPEED_I2CD_INTR_TX_NAK && > > + bus->slave_state == > > + ASPEED_I2C_SLAVE_READ_PROCESSED) { > > Either way, this needs a comment to explain what we're working around. > > > + irq_handled |= ASPEED_I2CD_INTR_TX_NAK; > > + i2c_slave_event(slave, I2C_SLAVE_STOP, > &value);
According the patch assume slave receive TX_NAK will be go to SLAVE_STOP state? > > + } > > irq_handled |= ASPEED_I2CD_INTR_SLAVE_MATCH; > > bus->slave_state = ASPEED_I2C_SLAVE_START; > > } > > -- > > 2.28.0 > > _______________________________________________ Openipmi-developer mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/openipmi-developer
