Re: [PATCH] i2c: xiic: Make the start and the byte count write atomic

From: Shubhrajyoti Datta
Date: Thu Sep 06 2018 - 03:08:24 EST


Hi,

On Tue, Sep 4, 2018 at 9:41 PM Wolfram Sang <wsa@xxxxxxxxxxxxx> wrote:
>
> On Mon, Sep 03, 2018 at 03:11:11PM +0530, shubhrajyoti.datta@xxxxxxxxx wrote:
> > From: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
> >
> > Disable interrupts while configuring the transfer and enable them back.
> >
> > We have below as the programming sequence
> > 1. start and slave address
> > 2. byte count and stop
> >
> > In some customer platform there was a lot of interrupts between 1 and 2
> > and after slave address (around 7 clock cyles) if 2 is not executed
> > then the transaction is nacked.
> >
> > To fix this case make the 2 writes atomic.
> >
> > Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
> > Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
>
> I assume simply changing the order of the register writes won't fix it?
No that is not possible.
>
> I also assume this is stable material?
>
Yes let me know if you want me to resend with the stable tag?