Re: [PATCH v3 1/1] i2c: ocores: fix polling mode workaround on FU540-C000 SoC
From: Peter Korsgaard
Date: Thu Oct 15 2020 - 10:49:15 EST
>>>>> "Sagar" == Sagar Shrikant Kadam <sagar.kadam@xxxxxxxxxx> writes:
> The FU540-C000 has a broken IRQ and support was added earlier
> so that it will operate in polling mode, but seems to work only
> in case interrupts property is missing from the i2c0 dt-node.
> This should not be the case and the driver should handle polling
> mode with the interrupt property present in i2c0 node of the
> device tree.
> So check if it's the FU540-C000 soc and enable polling mode master
> xfers, as the IRQ for this chip is broken.
> Fixes commit c45d4ba86731 ("i2c: ocores: add polling mode workaround
> for Sifive FU540-C000 SoC")
> Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@xxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-ocores.c | 22 +++++++++++++---------
> 1 file changed, 13 insertions(+), 9 deletions(-)
> diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
> index f5fc75b..1dab02d 100644
> --- a/drivers/i2c/busses/i2c-ocores.c
> +++ b/drivers/i2c/busses/i2c-ocores.c
> @@ -686,17 +686,21 @@ static int ocores_i2c_probe(struct platform_device *pdev)
> init_waitqueue_head(&i2c->wait);
> + /*
> + * Set OCORES_FLAG_BROKEN_IRQ to enable workaround for
> + * FU540-C000 SoC in polling mode.
> + * Since the SoC does have interrupt its dt has the interrupt
> + * defined but it should be bypassed in driver as this SoC has
NIT: Looks like there some commas missing and the wording sounds a bit
odd to me. What about E.G.:
/*
* Since the SoC does have an interrupt, its DT has an interrupt
* property - But this should be bypassed as the IRQ logic in this
* SoC is broken.
*/
> + * a broken IRQ, hence update the master_xfer to use polling
> + * transfers.
> + */
> + if (of_device_is_compatible(pdev->dev.of_node,
> + "sifive,fu540-c000-i2c"))
> + i2c->flags |= OCORES_FLAG_BROKEN_IRQ;
> +
> irq = platform_get_irq(pdev, 0);
> - if (irq == -ENXIO) {
> + if (i2c->flags & OCORES_FLAG_BROKEN_IRQ || irq == -ENXIO) {
Alternatively you can move it after the irq = platform_get_irq(pdev, 0)
line and just clear irq, E.G.:
irq = platform_get_irq(pdev, 0);
if (of_device_is_compatible(..)) {
i2c->flags |= OCORES_FLAG_BROKEN_IRQ;
irq = -ENXIO;
}
if (irq == -ENXIO) {
..
--
Bye, Peter Korsgaard