From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:57080 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750996AbeACToV (ORCPT ); Wed, 3 Jan 2018 14:44:21 -0500 Date: Wed, 3 Jan 2018 20:44:25 +0100 From: Greg KH To: Brian Norris Cc: jonathanh@nvidia.com, bleung@chromium.org, dianders@chromium.org, lee.jones@linaro.org, stable@vger.kernel.org, stable-commits@vger.kernel.org Subject: Re: Patch "mfd: cros ec: spi: Don't send first message too soon" has been added to the 3.18-stable tree Message-ID: <20180103194425.GC25621@kroah.com> References: <15143882673143@kroah.com> <20180103184920.GA217657@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180103184920.GA217657@google.com> Sender: stable-owner@vger.kernel.org List-ID: 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 know about it. > > > > > > From 15d8374874ded0bec37ef27f8301a6d54032c0e5 Mon Sep 17 00:00:00 2001 > > From: Jon Hunter > > Date: Tue, 14 Nov 2017 14:43:27 +0000 > > Subject: mfd: cros ec: spi: Don't send first message too soon > > > > From: Jon Hunter > > > > 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 > > Reviewed-by: Brian Norris > > Reviewed-by: Douglas Anderson > > Acked-by: Benson Leung > > Signed-off-by: Lee Jones > > Signed-off-by: Greg Kroah-Hartman > > > > --- > > 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 > > #include > > > > + 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