Hello Uwe,
On Thursday, 17 September 2020, 16:02:35 CEST, Uwe Kleine-König wrote:
> Hello,
>
> On Thu, Sep 17, 2020 at 02:20:27PM +0200, Christian Eggers wrote:
> ...
> > /* 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.
i.MX controllers require writing a 0 to clear these bits. Vybrid controllers
need writing a 1 for the same.
> 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?!)
This patch is only about using the correct processor specific value for
acknowledging an IRQ... But I think that returning EAGAIN (which aborts the
transfer) should be handling enough. At the next transfer, the controller will
be set back to master mode.
> 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
Christian
