From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jagan Teki Date: Wed, 12 Dec 2018 22:07:44 +0100 Subject: [U-Boot] [PATCH 03/16] spi: Add non DM version of SPI_MEM In-Reply-To: <20181212220205.4ad00b36@bbrezillon> References: <20181212173228.12281-1-vigneshr@ti.com> <20181212173228.12281-4-vigneshr@ti.com> <20181212214035.43b825b3@bbrezillon> <20181212220205.4ad00b36@bbrezillon> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Wed 12 Dec, 2018, 10:02 PM Boris Brezillon On Thu, 13 Dec 2018 02:15:16 +0530 > Jagan Teki wrote: > > > On Thu, Dec 13, 2018 at 2:10 AM Boris Brezillon > > wrote: > > > > > > Hi Jagan, > > > > > > On Thu, 13 Dec 2018 01:55:08 +0530 > > > Jagan Teki wrote: > > > > > > > On Wed, Dec 12, 2018 at 11:08 PM Vignesh R > wrote: > > > > > > > > > > Add non DM version of SPI_MEM to support easy migration to new SPI > NOR > > > > > framework. This can be removed once DM_SPI conversion is > complete. > > > > > > > > Our intention to use new driver to follow dm, why we need to support > > > > non-dm? any usecases? > > > > > > Looks like we're having the same discussion over and over. Vignesh is > > > dropping spi_flash.c which AFAICT was not depending on DM_SPI, so, if > > > we want to keep everyone happy while getting rid of some legacy code, > > > that's the only solution. DM conversion is a nice goal, but it's kind > > > of orthogonal to what Vignesh is working on. If DM_SPI conversion > > > happens before the spi-nor stuff is merged (which I doubt) then this > > > patch can simply be dropped. > > > > spi_flash.c is a core code not a specific driver it belongs. spi-mem > > is new feature driver how come new driver will support legacy non-dm > > do we have legacy use for that(ie what I'm asking about usecase) > > I recommend that you read the spi-mem code carefully. spi-mem is not > driver specific, it's a thin layer on top of spi and driver *can* (but > are not forced to) provide optimized methods to execute spi-mem > operations. When that's not the case, the implementation falls back to > regular spi transfers. AFAIK, both DM and non-DM drivers support > regular spi transfers, right? So why should we depend on DM_SPI? And > more importantly, if we do that, that means we can't get rid of > spi_flash.c since some users might still have non-DM SPI drivers, which > in turn means we keep more legacy code for no good reasons. > I understand spi-mem is core file, but new code too. > You want non-DM SPI controller drivers to go away, then remove them, > instead of blocking other changes using this excuse. > Please understand uboot development flow, legacy driver can be removed if possible once migration expire and NEW drivers or code must be dm driven. >