From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Arseniy Krasnov <avkrasnov@sberdevices.ru>
Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
Liang Yang <liang.yang@amlogic.com>,
Richard Weinberger <richard@nod.at>,
Vignesh Raghavendra <vigneshr@ti.com>,
Neil Armstrong <neil.armstrong@linaro.org>,
Kevin Hilman <khilman@baylibre.com>,
Jerome Brunet <jbrunet@baylibre.com>,
Jianxin Pan <jianxin.pan@amlogic.com>,
Yixun Lan <yixun.lan@amlogic.com>, <oxffffaa@gmail.com>,
<kernel@sberdevices.ru>, <linux-mtd@lists.infradead.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-amlogic@lists.infradead.org>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 6/6] mtd: rawnand: meson: rename node for chip select
Date: Thu, 11 May 2023 11:12:04 +0200 [thread overview]
Message-ID: <20230511111204.0b0b3d70@xps-13> (raw)
In-Reply-To: <6918ed54-3929-4832-1e93-6eb55b75c82b@sberdevices.ru>
Hi Arseniy,
avkrasnov@sberdevices.ru wrote on Thu, 11 May 2023 11:59:07 +0300:
> On 10.05.2023 23:53, Miquel Raynal wrote:
>
> Hello Martin, Miquel
>
> > Hi Martin & Arseniy,
> >
> > martin.blumenstingl@googlemail.com wrote on Wed, 10 May 2023 22:40:37
> > +0200:
> >
> >> Hello Arseniy,
> >>
> >> On Wed, May 10, 2023 at 1:13 PM Arseniy Krasnov
> >> <AVKrasnov@sberdevices.ru> wrote:
> >>>
> >>> This renames node with values for chip select from "reg" to "cs". It is
> >>> needed because when OTP access is enabled on the attached storage, MTD
> >>> subsystem registers this storage in the NVMEM subsystem. NVMEM in turn
> >>> tries to use "reg" node in its own manner, supposes that it has another
> >>> layout. All of this leads to device initialization failure.
> >> In general: if we change the device-tree interface (in this case:
> >> replacing a "reg" with a "cs" property) the dt-bindings have to be
> >> updated as well.
> >
> > True, and I would add, bindings should not be broken.
>
> I see, that's true. That is bad way to change bindings.
>
> >
> >> Documentation/devicetree/bindings/mtd/nand-controller.yaml and
> >> Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml show
> >> that the chip select of a NAND chip is specified with a "reg"
> >> property.
> >
> > All NAND controller binding expect the chip-select to be in the
> > 'reg' property, very much like a spi device would use reg to store the
> > cs as well: the reg property tells you how you address the device.
> >
> > I also fully agree with Martin's comments below. Changing reg is likely
> > a wrong approach :)
> >
> >> Also the code has to be backwards compatible with old .dtbs.
> >>
> >>> Example:
> >>>
> >>> [...] nvmem mtd0-user-otp: nvmem: invalid reg on /soc/bus@ffe00000/...
> >>> [...] mtd mtd0: Failed to register OTP NVMEM device
> >>> [...] meson-nand ffe07800.nfc: failed to register MTD device: -22
> >>> [...] meson-nand ffe07800.nfc: failed to init NAND chips
> >>> [...] meson-nand: probe of ffe07800.nfc failed with error -22
> >> This is odd - can you please share your definition of the &nfc node?
>
> Sure, here it is:
>
> mtd_nand: nfc@7800 {
> compatible = "amlogic,meson-axg-nfc";
> ...
> nand@0 {
> reg = <0>;
> };
> }
>
> I checked, that 'nand_set_flash_node()' is called with 'nand@0' and i suppose
> that it is correct (as You mentioned below). But, 'nvmem_add_cells_from_of()' is called
> with parent: 'nfc@7800', then it iterates over its childs, e.g. 'nand@0' and thus i get such
> situation. I guess, that 'nvmem_add_cells_from_of()' must be called with 'nand@0' ?
We recently had issues with nvmem parsing, but I believe a mainline
kernel should now be perfectly working on this regard. What version of
the Linux kernel are you using?
Thanks,
Miquèl
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next prev parent reply other threads:[~2023-05-11 9:12 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-10 11:08 [PATCH v3 0/6] refactoring and fix for Meson NAND Arseniy Krasnov
2023-05-10 11:08 ` [PATCH v3 1/6] mtd: rawnand: meson: fix command sequence for read/write Arseniy Krasnov
2023-05-10 11:08 ` [PATCH v3 2/6] mtd: rawnand: meson: move OOB to non-protected ECC area Arseniy Krasnov
2023-05-10 11:08 ` [PATCH v3 3/6] mtd: rawnand: meson: always read whole OOB bytes Arseniy Krasnov
2023-05-10 11:08 ` [PATCH v3 4/6] mtd: rawnand: meson: check buffer length Arseniy Krasnov
2023-05-10 11:08 ` [PATCH v3 5/6] mtd: rawnand: meson: remove unneeded bitwise OR with zeroes Arseniy Krasnov
2023-05-10 11:08 ` [PATCH v3 6/6] mtd: rawnand: meson: rename node for chip select Arseniy Krasnov
2023-05-10 20:40 ` Martin Blumenstingl
2023-05-10 20:53 ` Miquel Raynal
2023-05-11 8:59 ` Arseniy Krasnov
2023-05-11 9:12 ` Miquel Raynal [this message]
2023-05-11 9:17 ` Arseniy Krasnov
2023-05-11 10:16 ` Arseniy Krasnov
2023-05-11 12:11 ` Miquel Raynal
2023-05-11 14:22 ` Arseniy Krasnov
2023-05-12 14:49 ` Miquel Raynal
2023-05-13 13:22 ` Arseniy Krasnov
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