Re: [PATCH 3/5] i2c: aspeed: Mask IRQ status to relevant bits

From: Eddie James
Date: Tue Aug 25 2020 - 15:48:08 EST



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.


Thanks,

Eddie