From: Tao Ren <rentao.bupt@gmail.com>
To: Eddie James <eajames@linux.ibm.com>
Cc: Joel Stanley <joel@jms.id.au>,
devicetree <devicetree@vger.kernel.org>,
linux-aspeed <linux-aspeed@lists.ozlabs.org>,
dmitry.torokhov@gmail.com,
Brendan Higgins <brendanhiggins@google.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Rob Herring <robh+dt@kernel.org>,
linux-i2c@vger.kernel.org, linux-input@vger.kernel.org,
ryan_chen@aspeedtech.com
Subject: Re: [PATCH 3/5] i2c: aspeed: Mask IRQ status to relevant bits
Date: Tue, 25 Aug 2020 13:05:24 -0700 [thread overview]
Message-ID: <20200825200523.GA22083@taoren-ubuntu-R90MNF91> (raw)
In-Reply-To: <8fc365dd-8a89-9e5c-ed70-093ef2bf7265@linux.ibm.com>
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@linux.ibm.com> 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@linux.ibm.com>
> > > ---
> > > 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.
Cheers,
Tao
next prev parent reply other threads:[~2020-08-25 20:05 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-20 16:11 [PATCH 0/5] input: misc: Add IBM Operation Panel driver Eddie James
2020-08-20 16:11 ` [PATCH 1/5] dt-bindings: input: Add documentation for IBM Operation Panel Eddie James
2020-09-01 6:01 ` Joel Stanley
2020-09-08 20:37 ` Rob Herring
2020-08-20 16:11 ` [PATCH 2/5] input: misc: Add IBM Operation Panel driver Eddie James
2020-09-01 5:58 ` Joel Stanley
2020-09-01 6:11 ` Wolfram Sang
2020-09-02 15:47 ` Eddie James
2020-08-20 16:11 ` [PATCH 3/5] i2c: aspeed: Mask IRQ status to relevant bits Eddie James
2020-08-21 5:54 ` Wolfram Sang
2020-08-25 6:38 ` Joel Stanley
2020-08-25 19:47 ` Eddie James
2020-08-25 20:05 ` Tao Ren [this message]
2020-08-26 1:59 ` Ryan Chen
2020-08-20 16:11 ` [PATCH 4/5] ARM: dts: Aspeed: Tacoma: Add IBM Operation Panel I2C device Eddie James
2020-09-01 6:00 ` Joel Stanley
2020-09-01 6:11 ` Wolfram Sang
2020-08-20 16:11 ` [PATCH 5/5] ARM: dts: Aspeed: Rainier: " Eddie James
2020-09-01 6:01 ` Joel Stanley
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