From: andrew@lunn.ch (Andrew Lunn)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 00/34] pinctrl: mvebu: numerous fixes, cleanups and improvements
Date: Tue, 9 Jun 2015 23:36:15 +0200 [thread overview]
Message-ID: <20150609213615.GA32336@lunn.ch> (raw)
In-Reply-To: <20150609223456.0f569869@free-electrons.com>
> > What does pinctrl do when you ask for a pin which is not a member of the
> > function? If it silently ignores it, not a problem. But i expect it
> > actually throws an error. I could be wrong here, but it looks like it
> > is the mvebu code which checks if a pin is a member of a function. So
> > it might be possible to set the value of the val in the
> > mvebu_mpp_ctrl_setting to 0xff for the removed NAND pins, and when we
> > see such a value, print a warning about outdated DT, and "succeed"
> > rather than return an error.
>
> This can only work if the function number is not actually used. For
> example, in the very first patch "pinctrl: mvebu: armada-38x: fix PCIe
> functions" :
>
> - MPP_VAR_FUNCTION(4, "pcie1", "rstout", V_88F6820_PLUS),
> + MPP_VAR_FUNCTION(4, "ge0", "txerr", V_88F6810_PLUS),
>
> So the function 4 used to be pcie1, which you would like to still be
> supported, but it's now actually used for ge0.
Isn't 4 a function of the hardware? So this never worked. It is a
bug. So the DT file must also have a bug if this actually affects
anybody. So i would say, no backwards compatibility is required here.
> To be honest, I actually prefer that people updating their kernel and
> using an old DT get an error about pin muxing, rather than having the
> driver silently ignore and have people never update their Device Tree.
I also think many people will be keeping there DT file in step with
the kernel. Both get read from /boot by u-boot, or are appended to the
kernel, etc. I doubt there are many Marvell systems which a chunk of
FLASH dedicated to holding the DT blob.
> It's also about long term maintainability. Do we want to keep old crap
> around forever in all device drivers?
>
> > For spi -> spi0 it seems messier. So i would leave it as spi with a
> > comment, and add spi1.
>
> I'm fine with that.
>
> What about tdm2c -> tdm renaming on Armada 38x, and tdm-1 -> tdm for one
> single TDM pin on Armada XP ?
Is there an in-kernel use of TDM? I don't think so. So i would just
change them.
> I think we're hitting the limits of the DT backward compatibility: our
> description of the hardware had some bugs. What do we do? Continue to
> support bugs?
For true bugs, i say no, we fix it. Renames for which there is no
in-kernel user, just do it. But where there are in-kernel users, which
are not Marvell development boards, we should at least see if there is
a simple and not too ugly way to keep backwards compatibility, and
issue a strong warning it is time to upgrade.
Andrew
next prev parent reply other threads:[~2015-06-09 21:36 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-09 16:46 [PATCH 00/34] pinctrl: mvebu: numerous fixes, cleanups and improvements Thomas Petazzoni
2015-06-09 16:46 ` [PATCH 01/34] pinctrl: mvebu: armada-38x: fix PCIe functions Thomas Petazzoni
2015-06-09 16:46 ` Thomas Petazzoni
2015-06-10 8:51 ` Linus Walleij
2015-06-10 8:51 ` Linus Walleij
2015-06-09 16:46 ` [PATCH 02/34] pinctrl: mvebu: armada-370: fix spi0 pin description Thomas Petazzoni
2015-06-09 16:46 ` Thomas Petazzoni
2015-06-10 8:52 ` Linus Walleij
2015-06-10 8:52 ` Linus Walleij
2015-06-09 16:46 ` [PATCH 03/34] pinctrl: mvebu: armada-375: remove non-existing NAND re/we pins Thomas Petazzoni
2015-06-09 16:46 ` Thomas Petazzoni
2015-06-09 16:58 ` Andrew Lunn
2015-06-09 16:58 ` Andrew Lunn
2015-06-16 13:17 ` Thomas Petazzoni
2015-06-16 13:17 ` Thomas Petazzoni
2015-06-10 8:54 ` Linus Walleij
2015-06-10 8:54 ` Linus Walleij
2015-06-09 16:46 ` [PATCH 04/34] pinctrl: mvebu: armada-xp: remove non-existing NAND pins Thomas Petazzoni
2015-06-09 16:46 ` Thomas Petazzoni
2015-06-09 16:46 ` [PATCH 05/34] pinctrl: mvebu: armada-xp: remove non-existing VDD cpu_pd functions Thomas Petazzoni
2015-06-09 16:46 ` Thomas Petazzoni
2015-06-10 8:55 ` Linus Walleij
2015-06-10 8:55 ` Linus Walleij
2015-06-09 16:46 ` [PATCH 06/34] pinctrl: mvebu: armada-xp: fix functions of MPP48 Thomas Petazzoni
2015-06-09 16:46 ` Thomas Petazzoni
2015-06-09 16:46 ` [PATCH 07/34] pinctrl: mvebu: armada-375: remove incorrect space in pin description Thomas Petazzoni
2015-06-09 16:46 ` Thomas Petazzoni
2015-06-09 16:47 ` [PATCH 08/34] pinctrl: mvebu: armada-38x: fix incorrect total number of GPIOs Thomas Petazzoni
2015-06-09 16:47 ` Thomas Petazzoni
2015-06-10 8:57 ` Linus Walleij
2015-06-10 8:57 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 09/34] pinctrl: mvebu: armada-39x: " Thomas Petazzoni
2015-06-09 16:47 ` Thomas Petazzoni
2015-06-09 16:47 ` [PATCH 10/34] pinctrl: mvebu: armada-{375, 38x, 39x}: normalize naming of PTP subnames Thomas Petazzoni
2015-06-10 8:59 ` [PATCH 10/34] pinctrl: mvebu: armada-{375,38x,39x}: " Linus Walleij
2015-06-09 16:47 ` [PATCH 11/34] pinctrl: mvebu: armada-{38x, 39x, xp}: normalize naming of DRAM functions Thomas Petazzoni
2015-06-10 9:08 ` [PATCH 11/34] pinctrl: mvebu: armada-{38x,39x,xp}: " Linus Walleij
2015-06-09 16:47 ` [PATCH 12/34] pinctrl: mvebu: armada-39x: normalize SATA present functionality naming Thomas Petazzoni
2015-06-10 9:09 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 13/34] pinctrl: mvebu: armada-39x: normalize SDIO pin naming Thomas Petazzoni
2015-06-10 9:10 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 14/34] pinctrl: mvebu: armada-{370, 375, 38x, 39x}: normalize dev pins Thomas Petazzoni
2015-06-10 9:11 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 15/34] pinctrl: mvebu: armada-39x: align NAND pin naming Thomas Petazzoni
2015-06-10 9:12 ` Linus Walleij
2015-06-10 9:15 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 16/34] pinctrl: mvebu: armada-{370, 375, 38x, 39x, xp}: normalize TDM pins Thomas Petazzoni
2015-06-10 11:36 ` [PATCH 16/34] pinctrl: mvebu: armada-{370,375,38x,39x,xp}: " Linus Walleij
2015-06-09 16:47 ` [PATCH 17/34] pinctrl: mvebu: armada-{370,375}: normalize PCIe pins Thomas Petazzoni
2015-06-10 11:43 ` [PATCH 17/34] pinctrl: mvebu: armada-{370, 375}: " Linus Walleij
2015-06-09 16:47 ` [PATCH 18/34] pinctrl: mvebu: armada-{370,375}: normalize audio pins Thomas Petazzoni
2015-06-10 11:44 ` [PATCH 18/34] pinctrl: mvebu: armada-{370, 375}: " Linus Walleij
2015-06-09 16:47 ` [PATCH 19/34] pinctrl: mvebu: armada-{370, xp}: normalize ethernet txclkout pins Thomas Petazzoni
2015-06-10 11:50 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 20/34] pinctrl: mvebu: armada-xp: fix binding documentation of ge1 pins Thomas Petazzoni
2015-06-10 11:56 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 21/34] pinctrl: mvebu: armada-370: align VDD cpu-pd pin naming with datasheet Thomas Petazzoni
2015-06-10 11:57 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 22/34] pinctrl: mvebu: armada-370: align spi1 clock pin naming Thomas Petazzoni
2015-06-10 12:00 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 23/34] pinctrl: mvebu: armada-xp: rename spi to spi0 Thomas Petazzoni
2015-06-09 16:53 ` Andrew Lunn
2015-06-10 12:02 ` Linus Walleij
2015-06-10 12:01 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 24/34] pinctrl: mvebu: armada-39x: normalize ref clock naming Thomas Petazzoni
2015-06-10 12:09 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 25/34] pinctrl: mvebu: armada-xp: add spi1 function Thomas Petazzoni
2015-06-10 12:10 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 26/34] pinctrl: mvebu: armada-xp: add nand rb function Thomas Petazzoni
2015-06-10 12:11 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 27/34] pinctrl: mvebu: armada-xp: add dram functions Thomas Petazzoni
2015-06-10 12:12 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 28/34] pinctrl: mvebu: armada-38x: add sata functions Thomas Petazzoni
2015-06-10 12:24 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 29/34] pinctrl: mvebu: armada-38x: add nand functions Thomas Petazzoni
2015-06-10 12:25 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 30/34] pinctrl: mvebu: armada-38x: add ua1 functions Thomas Petazzoni
2015-06-10 12:30 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 31/34] pinctrl: mvebu: armada-38x: add ptp functions Thomas Petazzoni
2015-06-10 12:31 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 32/34] pinctrl: mvebu: armada-39x: add missing PCIe functions Thomas Petazzoni
2015-06-10 12:32 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 33/34] pinctrl: mvebu: armada-39x: add missing SATA functions Thomas Petazzoni
2015-06-10 12:35 ` Linus Walleij
2015-06-09 16:47 ` [PATCH 34/34] pinctrl: mvebu: armada-39x: add support for Armada 395 variant Thomas Petazzoni
2015-06-10 12:37 ` Linus Walleij
2015-06-09 17:01 ` [PATCH 00/34] pinctrl: mvebu: numerous fixes, cleanups and improvements Andrew Lunn
2015-06-09 19:22 ` Thomas Petazzoni
2015-06-09 19:47 ` Andrew Lunn
2015-06-09 20:34 ` Thomas Petazzoni
2015-06-09 21:36 ` Andrew Lunn [this message]
2015-06-10 8:08 ` Thomas Petazzoni
2015-06-10 12:39 ` Linus Walleij
2015-06-13 15:53 ` Gregory CLEMENT
2015-06-29 10:49 ` Linus Walleij
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