Re: [PATCH] i2c-omap: Double clear of ARDY status in IRQ handler

[Kevin Hilman <khilman-l0cyMroinI0@public.gmane.org>]

Keerthy <j-keerthy-l0cyMroinI0@public.gmane.org> writes:

> From: Richard woodruff <r-woodruff2-l0cyMroinI0@public.gmane.org>
>
> ProDB00017052 - ARDY interrupt reasserted after being cleared.

> This errata caused intermittent i2c instabilty(1 error per 3 hours) on several
> customer platforms. After applying the workaround the intermittent errors were
> not seen. This is not captured in the usual errata documents.

This (presumably internal) ProDB number above is meaningless in the
public changelog.  In lieu of a public erratum number, just summarize
the erratum/instability seen, references to other relevant public
errata (if any) would be useful too.   IOW, "instability" isn't quite
accurate enough.  A more detailed description of the problem/instability
is needed.

Thanks,

Kevin

>
> The workaround is to have a double clear of ARDY status in
> irq handler.
>
> Signed-off-by: Richard woodruff <r-woodruff2-l0cyMroinI0@public.gmane.org>
> Signed-off-by: Keerthy <j-keerthy-l0cyMroinI0@public.gmane.org>
> ---
>  drivers/i2c/busses/i2c-omap.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index 445de08..9bcefae 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -851,7 +851,8 @@ complete:
>  					OMAP_I2C_STAT_AL)) {
>  			omap_i2c_ack_stat(dev, stat &
>  				(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
> -				OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
> +				OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR |
> +				OMAP_I2C_STAT_ARDY));
>  			omap_i2c_complete_cmd(dev, err);
>  			return IRQ_HANDLED;
>  		}