From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lukasz Majewski Date: Mon, 17 Jun 2019 16:57:57 +0200 Subject: [U-Boot] [PATCH v3 5/5] ARM: dm: spi: Add support DM/DTS for i.MX28 mxs SPI driver (DM_SPI conversion) In-Reply-To: References: <20190615223442.12246-1-lukma@denx.de> <20190615223442.12246-6-lukma@denx.de> <8dab7d56-6954-5b2e-ec70-916307784758@denx.de> <20190617084813.2b3c9df3@jawa> <2feaae70-4bdd-09d8-3176-3c6a74e5d645@denx.de> <20190617142738.2f262d08@jawa> <000b54e7-7a4f-9c4c-d362-201f93d0e45f@denx.de> <20190617154129.39c29b67@jawa> Message-ID: <20190617165757.1dce3edf@jawa> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Marek, > On 6/17/19 3:41 PM, Lukasz Majewski wrote: > > On Mon, 17 Jun 2019 15:23:55 +0200 > > Marek Vasut wrote: > > > >> On 6/17/19 2:27 PM, Lukasz Majewski wrote: > >>> Hi Marek, > >>> > >>>> On 6/17/19 8:49 AM, Lukasz Majewski wrote: > >>>>> Hi Marek, > >>>>> > >>>>>> On 6/16/19 12:34 AM, Lukasz Majewski wrote: > >>>>>>> This commit converts mxs_spi driver to support DM/DTS. > >>>>>>> > >>>>>>> Signed-off-by: Lukasz Majewski > >>>>>> > >>>>>> Is the non-DM part needed for anything ? > >>>>> > >>>>> Do you mean the non-DM part of the mxs_gpio driver? Yes, it is > >>>>> used by not converted boards. > >>>> > >>>> This is a SPI driver though. > >>>> > >>>>>> I recall the SPL jumps back > >>>>>> to BootROM when loading the U-Boot proper. So if not, drop it. > >>>>>> > >>>>>> Also, please don't do partial conversion for iMX28 only, do the > >>>>>> iMX23 part as well, it cannot be hard. > >>>>> > >>>>> Maybe it is not hard, but I cannot test it properly as I don't > >>>>> have i.MX23 device. If you are offering your help with testing > >>>>> (i.e. you do have the access to i.MX23 device and you will test > >>>>> those changes) I can add support for it. > >>>>> > >>>>> Otherwise, NO, I will not add ANY new untested code. > >>>> > >>>> In general, you don't have to add any code, the iMX23/28 SPI IP > >>>> is very much the same hardware, DTTO for most of the other > >>>> blocks. If there are any differences between iMX23/28, they are > >>>> already handled in the existing driver(s). > >>>> > >>>> Half-way converted drivers in fact increase maintenance burden, > >>>> because then we have to deal with two different variants of the > >>>> code, instead of only one. > >>> > >>> I cannot agree with this sentence. > >> > >> Do you think maintaining - one DM driver which supports both iMX23 > >> and iMX28 - is more burden than maintaining - one driver which > >> supports DM, but only for iMX28 and non-DM for iMX23 and iMX28 ? I > >> don't think so. > >> > >>> The conversion would be done for > >>> i.MX28, which is then tested and validated (and clearly stated in > >>> the cover letter/commit message that only supported was i.MX28).> > >>> If I don't need to adjust common, reused code (which already > >>> supports both variants as it is the case with mxs_spi.c), then I > >>> don't mind. > >> > >> Well, that is what I said above, you don't. > > > > To make myself clear - If I can reuse the common code (which > > supports both imx23 and 28) for DM/DTS conversion then I'm OK with > > doing so. > > > > If you require me to add untested code specific to i.MX23 - then > > NO. > > Yes, you can. If possible, by reusing the old, common working code, I can add this to the converted driver. But I will not any new untested code. > > >> > >>> For more intrusive changes - the driver needs to be tested and > >>> validated (by somebody who has the HW for testing). > >> > >> That's up to board maintainers. > >> > >>>> That's why I would like to see this practice go > >>>> away wherever possible, and in this case it is possible. > >>> > >>> In this particular case it is possible to add support for both as > >>> SoC specific changes (i.MX23 vs i.MX28) is performed in common > >>> code (e.g. mxs_spi_xfer_dma). > >> > >> Both SPI and DMA blocks are basically the same on iMX23 and > >> iMX28. > > > > If I can reuse the common code, then I'm fine to do it. > > > >> > >>>> If you need someone to test your changes, CC the board > >>>> maintainers, that's standard practice. > >>> > >>> As fair as I remember only Angelo and Michael had also interest in > >>> testing converted code for i.MX28 based board. > >>> > >>> There was NO reply from other people when this (and few others) > >>> driver was marked as DEPRECATED. > >> > >> Well, too bad, clearly the interest in this platform is low. > > > > This means that people are using either some old U-Boot version, or > > there are a few people who want to refurbish the old HW with new > > code (e.g. Michael, Angelo). > > Yes > > >> That does not mean we should do sub-par upstream work, does it ? > >> > > > > We shall not add untested code. > > You cannot test every single platform in existence. Post patches and > let board maintainers test them ; if they won't, too bad, their > platform might become broken. There's no other way to move forward > without dragging behind a tremendous amount of ancient baggage, and > that in turn is not viable. > Best regards, Lukasz Majewski -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma at denx.de -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 488 bytes Desc: OpenPGP digital signature URL: