[PATCH 1/5] mtd/spinand: rework detect procedure for different READ_ID operation

[Michael Nazzareno Trimarchi]

Hi

On Tue, Apr 18, 2023 at 8:20 PM Mikhail Kshevetskiy
<mikhail.kshevetskiy at iopsys.eu> wrote:
>
> I can try to resend patches (flash drivers synced with linux-6.1).
> Unfortunately I am not sure I will be able to do it after changes in our
> mail system.

I don't think that re-sync now is what we want to do. The idea here is
to have easy patch that we can review.

We should go for this for now

Michael
>
> Mikhail Kshevetskiy
>
> On 18.04.2023 16:48, Michael Nazzareno Trimarchi wrote:
> > [External email]
> >
> >
> >
> >
> >
> > Hi Frieder
> >
> > On Tue, Apr 18, 2023 at 3:46 PM Frieder Schrempf
> > <frieder.schrempf at kontron.de> wrote:
> >> Hi Michael, Dario,
> >>
> >> On 28.03.23 09:57, Frieder Schrempf wrote:
> >>> Hi Michael,
> >>>
> >>> On 10.02.23 12:57, Michael Nazzareno Trimarchi wrote:
> >>>> Hi
> >>>>
> >>>> I will review
> >>>>
> >>>> On Thu, Feb 9, 2023 at 5:52 PM Tom Rini <trini at konsulko.com> wrote:
> >>>>> On Thu, Feb 09, 2023 at 10:24:47AM +0100, Frieder Schrempf wrote:
> >>>>>> Hi,
> >>>>>>
> >>>>>> On 10.01.23 12:58, Frieder Schrempf wrote:
> >>>>>>> From: Mikhail Kshevetskiy <mikhail.kshevetskiy at iopsys.eu>
> >>>>>>>
> >>>>>>> Currently there are 3 different variants of read_id implementation:
> >>>>>>> 1. opcode only. Found in GD5FxGQ4xF.
> >>>>>>> 2. opcode + 1 addr byte. Found in GD5GxGQ4xA/E
> >>>>>>> 3. opcode + 1 dummy byte. Found in other currently supported chips.
> >>>>>>>
> >>>>>>> Original implementation was for variant 1 and let detect function
> >>>>>>> of chips with variant 2 and 3 to ignore the first byte. This isn't
> >>>>>>> robust:
> >>>>>>>
> >>>>>>> 1. For chips of variant 2, if SPI master doesn't keep MOSI low
> >>>>>>> during read, chip will get a random id offset, and the entire id
> >>>>>>> buffer will shift by that offset, causing detect failure.
> >>>>>>>
> >>>>>>> 2. For chips of variant 1, if it happens to get a devid that equals
> >>>>>>> to manufacture id of variant 2 or 3 chips, it'll get incorrectly
> >>>>>>> detected.
> >>>>>>>
> >>>>>>> This patch reworks detect procedure to address problems above. New
> >>>>>>> logic do detection for all variants separatedly, in 1-2-3 order.
> >>>>>>> Since all current detect methods do exactly the same id matching
> >>>>>>> procedure, unify them into core.c and remove detect method from
> >>>>>>> manufacture_ops.
> >>>>>>>
> >>>>>>> This is a rework of Chuanhong Guo <gch981213 at gmail.com> patch
> >>>>>>> submitted to linux kernel
> >>>>>>>
> >>>>>>> Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy at iopsys.eu>
> >>>>>>> Signed-off-by: Frieder Schrempf <frieder.schrempf at kontron.de>
> >>>>>> +Cc: Jagan, Tom
> >>>>>>
> >>>>>> Who is supposed to pick up these patches? Some of them have been around
> >>>>>> for some months (before I resent them).
> >>>>>>
> >>>>>> There is no maintainer for drivers/mtd/spinand/ and no maintainer for
> >>>>>> drivers/mtd/ in general.
> >>>>>>
> >>>>>> In Patchwork Jagan got assigned, but the get_maintainer.pl script didn't
> >>>>>> even add him to Cc, of course.
> >>>>>>
> >>>>>> Any ideas how to proceed?
> >>>>> We don't have anyone dedicated to that area, yes, sadly. I've added
> >>>>> Michael and Dario as they've also been doing mtd-but-not-spi work of
> >>>>> late to see if they're interested. Or since you've long been working
> >>>>> here, would you like to more formally maintain the area? Thanks!
> >>>> They can come from our tree. I will try to sort out all my duties weeked
> >>> Any news regarding reviewing/picking these patches?
> >> Ping!
> >>
> >> Can you please apply these patches, that have been waiting for so long?
> >>
> >> Thanks
> >> Frieder
> > Yes, waiting for Jagan, please way 1 day more
> >
> > Michael



-- 
Michael Nazzareno Trimarchi
Co-Founder & Chief Executive Officer
M. +39 347 913 2170
michael at amarulasolutions.com
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