RE: [PATCH V7 3/6] i2c: qup: Transfer each i2c_msg in i2c_msgs without a stop bit

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Wolfram,

> -----Original Message-----
> From: linux-arm-kernel [mailto:linux-arm-kernel-
> bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of Wolfram Sang
> Sent: Friday, February 05, 2016 1:39 AM
> To: Sricharan
> Cc: devicetree@xxxxxxxxxxxxxxx; architt@xxxxxxxxxxxxxx; linux-arm-
> msm@xxxxxxxxxxxxxxx; ntelkar@xxxxxxxxxxxxxx; galak@xxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; andy.gross@xxxxxxxxxx; linux-
> i2c@xxxxxxxxxxxxxxx; iivanov@xxxxxxxxxx; agross@xxxxxxxxxxxxxx;
> dmaengine@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH V7 3/6] i2c: qup: Transfer each i2c_msg in i2c_msgs
> without a stop bit
> 
> Hi,
> 
> > Ah, so what I meant above is there is no 'STOP' bit between each msg
> > in i2c_msgs, but 'REAPEATED_START' still holds true.  We are sending
> > 'START' bit for each msg.
> > So these is how each msg in i2c_msg is sent,
> >
> > |------MSG1--------|-----MSG2---------|------MSG3------------|
> >
> >   |START|DATA|------|START|DATA|---|START|DATA|STOP|
> >
> > If my commit text does not make this clear, I  can reword that ?
> 
> OK, now this looks to me perfectly fine: A number of *messages*
> concatenated into one *transfer* by repeated start. That's the way it
should
> be.
> 
> So, I'd simply remove these words:
> 
> "The QUP i2c hardware has no way to inform that there should not be a
> 'STOP' at the end of transaction. The only way to implement this is to
> coalesce all the i2c_msg in i2c_msgs in to one transaction and transfer
them."
> 
> This sounded like the HW needed a special handling, so I was under the
> impression REP_START was broken. However, unless I misunderstood
> something again, this now sounds like the standard case and we can keep
> the commit message simple. If you are okay with that, I can update it
here,
> no need to resend.
> 
      Yes the above modified commit text looks perfect to be updated and
thanks
      for the update as well.

Regards,
 Sricharan

--
To unsubscribe from this list: send the line "unsubscribe dmaengine" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Kernel]     [Linux ARM (vger)]     [Linux ARM MSM]     [Linux Omap]     [Linux Arm]     [Linux Tegra]     [Fedora ARM]     [Linux for Samsung SOC]     [eCos]     [Linux PCI]     [Linux Fastboot]     [Gcc Help]     [Git]     [DCCP]     [IETF Announce]     [Security]     [Linux MIPS]     [Yosemite Campsites]

  Powered by Linux