From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Brezillon Subject: Re: [PATCH v4 06/10] ARM: defconfig: Use the new FSL QSPI driver under the SPI framework Date: Thu, 8 Nov 2018 09:34:51 +0100 Message-ID: <20181108093451.08dfe63e@bbrezillon> References: <1541601809-16950-1-git-send-email-frieder.schrempf@kontron.de> <1541601809-16950-7-git-send-email-frieder.schrempf@kontron.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Olof Johansson , "linux-mtd@lists.infradead.org" , "linux-spi@vger.kernel.org" , David Woodhouse , "Brian Norris" , Mark Vasut , Richard Weinberger , "miquel.raynal@bootlin.com" , Mark Brown , "david.wolfe@nxp.com" , Fabio Estevam , "prabhakar.kushwaha@nxp.com" , "yogeshnarayan.gaur@nxp.com" , "han.xu@nxp.com" , Shawn Guo , "frieder.schrempf@exceet.de" , Sascha Hauer , To: Schrempf Frieder Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org On Wed, 7 Nov 2018 16:36:13 +0000 Schrempf Frieder wrote: > Hi Olof, > > On 07.11.18 17:20, Olof Johansson wrote: > > On Wed, Nov 7, 2018 at 6:44 AM Frieder Schrempf > > wrote: > >> > >> From: Frieder Schrempf > >> > >> The new driver at spi/spi-fsl-qspi.c replaces the old SPI NOR driver > >> at mtd/fsl-quadspi.c. Switch to the new driver in the defconfigs. > >> > >> Signed-off-by: Frieder Schrempf > > > > Hi Frieder, > > > > This patch is part of a series that I didn't see the rest of, but in > > general we prefer to merge these through arm-soc even if the driver > > goes in through another tree. The way we'd prefer to handle it is that > > once the driver lands, we'll take the config option change to turn it > > on. To avoid our branches to break until both sides have landed, it > > might be a good idea to keep both drivers on for a short while (one > > release). > > > > So, I'm not going to ack this since we avoid taking defconfig changes > > through driver trees (these two defconfigs tend to churn a lot and we > > don't want to create merge conflicts where we don't have to), but > > we'll be happy to pick it up when the time comes. > > Ok, thank you for explaining the common practice. I will drop the config > changes for the next version and send it separately when the time is ready. > > Both the old driver and the new one use the same compatible strings for > probing. Wouldn't that cause problems if both drivers are enabled for a > while, or am I missing something? Or maybe we should not introduce a new Kconfig option and just reuse the old one. It probably requires re-ordering patches a bit (patch 1 should be moved after patch 5). Then you have 2 choices: 1/ merge patch 1 and 6 so that the new driver effectively replaces the old one but uses the same Kconfig option 2/ remove the ability to compile the old driver when the new one is introduced: remove the line from drivers/mtd/spi-nor Makefile and move the Kconfig entry from drivers/mtd/spi-nor/Kconfig to drivers/spi/Kconfig. And remove the old code in a separate patch I'm fine either way, but option #2 will probably make the patch introducing the new driver bigger and hurt readability.