Messages in this thread |  | | Date | Fri, 16 Dec 2022 11:41:08 +0100 | Subject | Re: [PATCH] i2c: imx: increase retries on arbitration loss | From | Primoz Fiser <> |
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Hi Marco,
On 16. 12. 22 10:45, Marco Felsch wrote: > Hi Primoz, > > On 22-12-16, Primoz Fiser wrote: >> By default, retries value is set to 0 (no retries). Set retries to more >> sensible value of 3 to allow i2c core to re-attempt transfer in case of >> i2c arbitration loss (i2c-imx returns -EAGAIN errno is such case). > > apart the fact that the number of retries vary a lot and so the client > driver behaviour can vary a lot which is not good IMHO, why do you think > that 3 is a sufficient number?
IMHO it is better than leaving it at 0 (no retries)?
Setting it to sensible value like 3 will at least attempt to make transfer in case arbitration-loss occurs.
> > If an arbitration loss happen, why do you think that retrying it 3 times > changes that?
I our case, setting retries to non-zero value solves issues with PMIC shutdown on phyboard-mira which in some rare cases fails with "Failed to shutdown (err = -11)" (-EAGAIN).
To me it makes common sense retries is set to non-zero value especially for such rare conditions/situations.
BR, Primoz
> > Regards, > Marco > > >> >> Signed-off-by: Primoz Fiser <primoz.fiser@norik.com> >> --- >> 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 cf5bacf3a488..6a5694cfe1cc 100644 >> --- a/drivers/i2c/busses/i2c-imx.c >> +++ b/drivers/i2c/busses/i2c-imx.c >> @@ -1478,6 +1478,7 @@ static int i2c_imx_probe(struct platform_device *pdev) >> i2c_imx->adapter.dev.parent = &pdev->dev; >> i2c_imx->adapter.nr = pdev->id; >> i2c_imx->adapter.dev.of_node = pdev->dev.of_node; >> + i2c_imx->adapter.retries = 3; >> i2c_imx->base = base; >> ACPI_COMPANION_SET(&i2c_imx->adapter.dev, ACPI_COMPANION(&pdev->dev)); >> >> -- >> 2.25.1 >> >> >>
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