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SubjectRe: [PATCH v2] i2c: mediatek: disable zero-length transfers for mt8183
On Thu, Aug 22, 2019 at 05:45:17PM +0800, Hsin-Yi Wang wrote:
> When doing i2cdetect quick write mode, we would get transfer
> error ENOMEM, and i2cdetect shows there's no device at the address.
> Quoting from mt8183 datasheet, the number of transfers to be
> transferred in one transaction should be set to bigger than 1,
> so we should forbid zero-length transfer and update functionality.
>
> Incorrect return:
> localhost ~ # i2cdetect -q -y 0
> 0 1 2 3 4 5 6 7 8 9 a b c d e f
> 00: -- -- -- -- -- -- -- -- -- -- -- -- --
> 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> 70: -- -- -- -- -- -- -- --
>
> After this patch:
> localhost ~ # i2cdetect -q -y 0
> Error: Can't use SMBus Quick Write command on this bus
>
> localhost ~ # i2cdetect -y 0
> Warning: Can't use SMBus Quick Write command, will skip some addresses
> 0 1 2 3 4 5 6 7 8 9 a b c d e f
> 00:
> 10:
> 20:
> 30: -- -- -- -- -- -- -- --
> 40:
> 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> 60:
> 70:

Thanks for providing these test results. Much appreciated. To shorten
the commit log a little, I removed them before applying, though.

>
> Reported-by: Alexandru M Stan <amstan@chromium.org>
> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>

Applied to for-next, thanks!

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