Re: [PATCH v1 2/2] i2c: imx: ensure no clock is generated after last read

From: Frank Li

Date: Tue Mar 03 2026 - 10:58:45 EST


On Tue, Mar 03, 2026 at 10:14:08AM +0100, Stefan Eichenberger wrote:
> Hi Frank,
>
> On Wed, Feb 18, 2026 at 05:37:54PM +0100, Stefan Eichenberger wrote:
> > Hi Frank,
> >
> > On Wed, Feb 18, 2026 at 11:26:52AM -0500, Frank Li wrote:
> > > On Wed, Feb 18, 2026 at 04:08:50PM +0100, Stefan Eichenberger wrote:
> > > > From: Stefan Eichenberger <stefan.eichenberger@xxxxxxxxxxx>
> > > >
> > > > When reading from the I2DR register, right after releasing the bus by
> > > > clearing MSTA and MTX, the I2C controller might still generate an
> > > > additional clock cycle which can cause devices to misbehave. Ensure to
> > >
> > > Do you means SCL have additional toggle? You capture waveform?
> > >
> >
> > Yes exactly. We were able to capture the waveform when the issue
> > happens. It doesn't always happen though, it depends on how much time
> > passes between clearing MSTA and MTX and reading from I2DR.
> >
> > If you want to see the waveform, I uploaded it to our server:
> > https://share.toradex.com/dwnhcrl6b9toib6
> > You can see the additional clock at the right end, after "0x17 + NAK".
>
> Have you had a chance to look at the waveform? Do you have any concerns
> about the proposed solution?

I am fine. Add carlos, who did many work about I2C.

Frank
>
> Best regards,
> Stefan