> -----Original Message----- > From: Tao Ren [mailto:rentao.bupt@xxxxxxxxx] > Sent: Wednesday, August 26, 2020 4:05 AM > To: Eddie James <eajames@xxxxxxxxxxxxx> > Cc: Joel Stanley <joel@xxxxxxxxx>; devicetree <devicetree@xxxxxxxxxxxxxxx>; > linux-aspeed <linux-aspeed@xxxxxxxxxxxxxxxx>; dmitry.torokhov@xxxxxxxxx; > Brendan Higgins <brendanhiggins@xxxxxxxxxx>; Linux Kernel Mailing List > <linux-kernel@xxxxxxxxxxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>; > linux-i2c@xxxxxxxxxxxxxxx; linux-input@xxxxxxxxxxxxxxx; Ryan Chen > <ryan_chen@xxxxxxxxxxxxxx> > Subject: Re: [PATCH 3/5] i2c: aspeed: Mask IRQ status to relevant bits > > On Tue, Aug 25, 2020 at 02:47:51PM -0500, Eddie James wrote: > > > > On 8/25/20 1:38 AM, Joel Stanley wrote: > > > On Thu, 20 Aug 2020 at 16:12, Eddie James <eajames@xxxxxxxxxxxxx> > wrote: > > > > Mask the IRQ status to only the bits that the driver checks. This > > > > prevents excessive driver warnings when operating in slave mode > > > > when additional bits are set that the driver doesn't handle. > > > > > > > > Signed-off-by: Eddie James <eajames@xxxxxxxxxxxxx> > > > > --- > > > > drivers/i2c/busses/i2c-aspeed.c | 1 + > > > > 1 file changed, 1 insertion(+) > > > > > > > > diff --git a/drivers/i2c/busses/i2c-aspeed.c > > > > b/drivers/i2c/busses/i2c-aspeed.c index 31268074c422..abf40f2af8b4 > > > > 100644 > > > > --- a/drivers/i2c/busses/i2c-aspeed.c > > > > +++ b/drivers/i2c/busses/i2c-aspeed.c > > > > @@ -604,6 +604,7 @@ static irqreturn_t aspeed_i2c_bus_irq(int irq, > void *dev_id) > > > > writel(irq_received & ~ASPEED_I2CD_INTR_RX_DONE, > > > > bus->base + ASPEED_I2C_INTR_STS_REG); > > > > readl(bus->base + ASPEED_I2C_INTR_STS_REG); > > > > + irq_received &= 0xf000ffff; > > > > irq_remaining = irq_received; > > > This would defeat the check for irq_remaining. I don't think we want to do > this. > > > > > > Can you explain why these bits are being set in slave mode? > > > > > > No, I don't have any documentation for the bits that are masked off > > here, so I don't know why they would get set. > > > > The check for irq_remaining is still useful for detecting that the > > driver state machine might be out of sync with what the master is doing. > > I have a similar patch in my local tree, and the reason being: AST2600 I2C > Controller may set I2CD10[25:24] to report Current Slave Parking Status > (defined in new register I2CS24) even though the new register mode is off. The > 2 bits can be ignored in legacy mode, and Ryan from ASPEED could confirm it. Yes, in AST2600 i2cd10[25:24] will be the same with new mode register i2cs24[25:24] Thanks Tao. > > > Cheers, > > Tao
