diff options
| author | Eddie James <eajames@linux.ibm.com> | 2019-10-18 18:46:02 +0300 |
|---|---|---|
| committer | Joel Stanley <joel@jms.id.au> | 2019-12-12 01:29:58 +0300 |
| commit | 20572eecd7248b66d855a8e4812debd9f828ccba (patch) | |
| tree | a16f755623b3fec1527a562937f133b92058bc7c | |
| parent | c6846ad0e52a2d6d1e8a135d8e090860b9b40d38 (diff) | |
| download | linux-20572eecd7248b66d855a8e4812debd9f828ccba.tar.xz | |
i2c: aspeed: Prevent state corruption for IRQ with no status
On the AST2600, interrupts have been observed with no interrupt status
bits set. This can break the driver state machine, so these interrupts
should be detected and the handler should return IRQ_NONE.
This is a workaround and should not be merged upstream.
OpenBMC-Staging-Count: 1
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
| -rw-r--r-- | drivers/i2c/busses/i2c-aspeed.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c index a7be6f24450b..b63ecc20777e 100644 --- a/drivers/i2c/busses/i2c-aspeed.c +++ b/drivers/i2c/busses/i2c-aspeed.c @@ -600,6 +600,17 @@ static irqreturn_t aspeed_i2c_bus_irq(int irq, void *dev_id) spin_lock(&bus->lock); irq_received = readl(bus->base + ASPEED_I2C_INTR_STS_REG); + + /* + * On the AST2600, interrupts have been observed with no interrupt + * status bits set. In this case, the handler should return IRQ_NONE + * immediately to prevent driver state machine corruption. + */ + if (!irq_received) { + spin_unlock(&bus->lock); + return IRQ_NONE; + } + /* Ack all interrupts except for Rx done */ writel(irq_received & ~ASPEED_I2CD_INTR_RX_DONE, bus->base + ASPEED_I2C_INTR_STS_REG); |