Re: [PATCH v2] ahci: imx: Handle increased read failures for IMX53 temperature sensor in low frequency mode.

From: Tejun Heo
Date: Mon Nov 13 2017 - 15:18:17 EST


On Mon, Nov 13, 2017 at 10:31:01AM +0000, Martyn Welch wrote:
> From: Egor Starkov <egor.starkov@xxxxxx>
>
> Extended testing has shown that the imx ahci driver sometimes requires
> more than the 100 attempts currently alotted in the driver to perform a
> successful temperature reading when running at minimum (throttled) CPU
> frequency.
>
> Debugging suggests that the read cycle can take 160 attempts (which given
> that the driver averages 80 readings from the ADC equates to one failure
> on each read).
>
> Increase the attempt limit to 200 in order to greatly reduce the
> likelihood of the driver failing to perform a temperature reading,
> especially at low CPU frequency.
>
> Signed-off-by: Egor Starkov <egor.starkov@xxxxxx>
> Signed-off-by: Martyn Welch <martyn.welch@xxxxxxxxxxxxxxx>

Applied to libata/for-4.15.

Thanks.

--
tejun