| Message ID | 20200917122029.11121-2-ceggers@arri.de |
|---|---|
| State | New |
| Headers | show |
| Series | [1/3] i2c: imx: Fix reset of I2SR_IAL flag | expand |
Hello, On Thu, Sep 17, 2020 at 02:20:27PM +0200, Christian Eggers wrote: > According to the "VFxxx Controller Reference Manual" (and the comment > block starting at line 97), Vybrid requires writing a one for clearing > an interrupt flag. Syncing with the method for clearing I2SR_IIF in > i2c_imx_isr(). > > Signed-off-by: Christian Eggers <ceggers@arri.de> > Cc: stable@vger.kernel.org > --- > drivers/i2c/busses/i2c-imx.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c > index 0ab5381aa012..d8b2e632dd10 100644 > --- a/drivers/i2c/busses/i2c-imx.c > +++ b/drivers/i2c/busses/i2c-imx.c > @@ -425,6 +425,7 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool a > /* check for arbitration lost */ > if (temp & I2SR_IAL) { > temp &= ~I2SR_IAL; > + temp |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IAL); > imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR); > return -EAGAIN; This looks strange. First the flag is cleared and then it is (in some cases) set again. If I2SR_IIF is set in temp you ack this irq without handling it. (Which might happen if atomic is set and irqs are off?!) I see this idiom is used in a few more places in the driver already, I didn't check but these might have the same problem maybe? Best regards Uwe
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 0ab5381aa012..d8b2e632dd10 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -425,6 +425,7 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool a /* check for arbitration lost */ if (temp & I2SR_IAL) { temp &= ~I2SR_IAL; + temp |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IAL); imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR); return -EAGAIN; }
According to the "VFxxx Controller Reference Manual" (and the comment block starting at line 97), Vybrid requires writing a one for clearing an interrupt flag. Syncing with the method for clearing I2SR_IIF in i2c_imx_isr(). Signed-off-by: Christian Eggers <ceggers@arri.de> Cc: stable@vger.kernel.org --- drivers/i2c/busses/i2c-imx.c | 1 + 1 file changed, 1 insertion(+)