Re: Patch "mfd: cros ec: spi: Don't send first message too soon" has been added to the 3.18-stable tree

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Jan 03, 2018 at 10:49:21AM -0800, Brian Norris wrote:
> Hi Greg,
> 
> On Wed, Dec 27, 2017 at 04:24:27PM +0100, Greg Kroah-Hartman wrote:
> > 
> > This is a note to let you know that I've just added the patch titled
> > 
> >     mfd: cros ec: spi: Don't send first message too soon
> > 
> > to the 3.18-stable tree which can be found at:
> >     http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
> > 
> > The filename of the patch is:
> >      mfd-cros-ec-spi-don-t-send-first-message-too-soon.patch
> > and it can be found in the queue-3.18 subdirectory.
> > 
> > If you, or anyone else, feels it should not be added to the stable tree,
> > please let <stable@vger.kernel.org> know about it.
> > 
> > 
> > From 15d8374874ded0bec37ef27f8301a6d54032c0e5 Mon Sep 17 00:00:00 2001
> > From: Jon Hunter <jonathanh@nvidia.com>
> > Date: Tue, 14 Nov 2017 14:43:27 +0000
> > Subject: mfd: cros ec: spi: Don't send first message too soon
> > 
> > From: Jon Hunter <jonathanh@nvidia.com>
> > 
> > commit 15d8374874ded0bec37ef27f8301a6d54032c0e5 upstream.
> > 
> > On the Tegra124 Nyan-Big chromebook the very first SPI message sent to
> > the EC is failing.
> > 
> > The Tegra SPI driver configures the SPI chip-selects to be active-high
> > by default (and always has for many years). The EC SPI requires an
> > active-low chip-select and so the Tegra chip-select is reconfigured to
> > be active-low when the EC SPI driver calls spi_setup(). The problem is
> > that if the first SPI message to the EC is sent too soon after
> > reconfiguring the SPI chip-select, it fails.
> > 
> > The EC SPI driver prevents back-to-back SPI messages being sent too
> > soon by keeping track of the time the last transfer was sent via the
> > variable 'last_transfer_ns'. To prevent the very first transfer being
> > sent too soon, initialise the 'last_transfer_ns' variable after calling
> > spi_setup() and before sending the first SPI message.
> > 
> > Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
> > Reviewed-by: Brian Norris <briannorris@chromium.org>
> > Reviewed-by: Douglas Anderson <dianders@chromium.org>
> > Acked-by: Benson Leung <bleung@chromium.org>
> > Signed-off-by: Lee Jones <lee.jones@linaro.org>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > 
> > ---
> >  drivers/mfd/cros_ec_spi.c |    1 +
> >  1 file changed, 1 insertion(+)
> > 
> > --- a/drivers/mfd/cros_ec_spi.c
> > +++ b/drivers/mfd/cros_ec_spi.c
> > @@ -23,6 +23,7 @@
> >  #include <linux/slab.h>
> >  #include <linux/spi/spi.h>
> >  
> > +	ec_spi->last_transfer_ns = ktime_get_ns();
> 
> Umm, that's not even close to correct? You've stuck this line just below
> the headers... You may still need to adjust for some context changes in
> 3.18 vs. Linus' latest, but this should at least be in
> cros_ec_spi_probe().
> 
> (The kbuild bots are complaining about your RC branch.)

This was long fixed, did your email just sync?

thanks,

greg k-h