From: Abhishek Sahu <absahu@codeaurora.org>
To: Boris Brezillon <boris.brezillon@bootlin.com>
Cc: linux-arm-msm@vger.kernel.org,
Miquel Raynal <miquel.raynal@bootlin.com>,
linux-kernel@vger.kernel.org, Marek Vasut <marek.vasut@gmail.com>,
linux-mtd@lists.infradead.org,
Richard Weinberger <richard@nod.at>,
Andy Gross <andy.gross@linaro.org>,
Brian Norris <computersforpeace@gmail.com>,
David Woodhouse <dwmw2@infradead.org>
Subject: Re: [PATCH 2/5] mtd: rawnand: qcom: remove driver specific block_markbad function
Date: Fri, 09 Nov 2018 11:48:32 +0530 [thread overview]
Message-ID: <453b3e058e972dc0644f06c2f0969802@codeaurora.org> (raw)
In-Reply-To: <20181104165627.293773a8@bbrezillon>
On 2018-11-04 21:26, Boris Brezillon wrote:
> Hi Abhishek,
>
> On Fri, 20 Jul 2018 15:03:48 +0200
> Boris Brezillon <boris.brezillon@bootlin.com> wrote:
>
>> On Fri, 20 Jul 2018 17:46:38 +0530
>> Abhishek Sahu <absahu@codeaurora.org> wrote:
>>
>> > Hi Boris,
>> >
>> > On 2018-07-19 03:13, Boris Brezillon wrote:
>> > > On Wed, 18 Jul 2018 23:23:50 +0200
>> > > Miquel Raynal <miquel.raynal@bootlin.com> wrote:
>> > >
>> > >> Boris,
>> > >>
>> > >> Can you please check the change in qcom_nandc_write_oob() is
>> > >> valid? I think it is but as this is a bit of a hack I prefer double
>> > >> checking.
>> > >
>> > > Indeed, it's hack-ish.
>> > >
>> > >>
>> > >> Thanks,
>> > >> Miquèl
>> > >>
>> > >>
>> > >> Abhishek Sahu <absahu@codeaurora.org> wrote on Fri, 6 Jul 2018
>> > >> 13:21:56 +0530:
>> > >>
>> > >> > The NAND base layer calls write_oob() by setting bytes at
>> > >> > chip->badblockpos with value non 0xFF for updating bad block status.
>> > >> > The QCOM NAND controller skips the bad block bytes while doing normal
>> > >> > write with ECC enabled. When initial support for this driver was
>> > >> > added, the driver specific function was added temporarily for
>> > >> > block_markbad() with assumption to change for raw read in NAND base
>> > >> > layer. Moving to raw read for block_markbad() seems to take more time
>> > >> > so this patch removes driver specific block_markbad() function by
>> > >> > using following HACK in write_oob() function.
>> > >> >
>> > >> > Check for BBM bytes in OOB and accordingly do raw write for updating
>> > >> > BBM bytes in NAND flash or normal write for updating available OOB
>> > >> > bytes.
>> > >
>> > > Why don't we change that instead of patching the qcom driver to guess
>> > > when the core tries to mark a block bad? If you're afraid of breaking
>> > > existing drivers that might rely on the "write/read BBM in non-raw
>> > > mode" solution (I'm sure some drivers are), you can always add a new
>> > > flag in chip->options (NAND_ACCESS_BBM_IN_RAW_MODE) and only use raw
>> > > accessors when this flag is set.
>> > >
>> >
>> > We started with that Only
>> >
>> > http://patchwork.ozlabs.org/patch/508565/
>> >
>> > and since we didn't conclude, we went for driver
>> > specific bad block check and mark bad block functions.
>> >
>> > Now, we wanted to get rid of driver specific functions
>> >
>> > 1. For bad block check, we found the way to get the BBM bytes
>> > with ECC read. Controller updates BBM in separate register
>> > which we can read and update the same in OOB. Patch #1 of
>> > series does the same.
>> >
>> > 2. For bad block mark, there is no way to update in ECC mode
>> > that's why we went for HACK to get rid of driver specific
>> > function.
>> >
>> > If adding flag is fine now then this HACK won't be required.
>>
>> Yep. I'm fine with that. Can you rebase the patch you pointed out on
>> top
>> of nand/next and move the flag to chip->options instead of
>> chip->bbt_options + prefix it with NAND_ instead of NAND_BBT_?
>
> I'm currently trying to get rid of chip->block_bad() (now placed in
> chip->legacy.block_bad()), and I wanted to know if you were still
> planning to submit the changes we discussed in this thread. If you
> don't have time, please let me know and I'll try to do it.
>
Sorry Boris, I couldn't work on these patches.
Currently, I am working on non open source projects so
I can't submit any patches in open source till this project
completion due to legal guidelines.
If this is urgent then you can try. I will help in
QCOM related stuffs and testing.
Thanks,
Abhishek
next prev parent reply other threads:[~2018-11-09 6:18 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-06 7:51 [PATCH 0/5] Update for removing driver specific BBM functions Abhishek Sahu
2018-07-06 7:51 ` [PATCH 1/5] mtd: rawnand: qcom: remove driver specific bad block check function Abhishek Sahu
2018-07-06 7:51 ` [PATCH 2/5] mtd: rawnand: qcom: remove driver specific block_markbad function Abhishek Sahu
2018-07-18 21:23 ` Miquel Raynal
2018-07-18 21:43 ` Boris Brezillon
2018-07-20 12:16 ` Abhishek Sahu
2018-07-20 13:03 ` Boris Brezillon
2018-11-04 15:56 ` Boris Brezillon
2018-11-09 6:18 ` Abhishek Sahu [this message]
2018-07-06 7:51 ` [PATCH 3/5] mtd: rawnand: qcom: fix NAND register write errors Abhishek Sahu
2018-07-06 7:51 ` [PATCH 4/5] mtd: rawnand: qcom: update BBT related flags Abhishek Sahu
2018-07-18 21:15 ` Miquel Raynal
2018-07-18 21:36 ` Boris Brezillon
2018-07-18 21:41 ` Miquel Raynal
2018-07-18 21:42 ` Miquel Raynal
2018-07-20 7:14 ` Abhishek Sahu
2018-07-06 7:51 ` [PATCH 5/5] mtd: rawnand: qcom: reorganization by removing read/write helpers Abhishek Sahu
2018-07-18 21:29 ` Miquel Raynal
2018-07-18 21:54 ` Boris Brezillon
2018-07-28 10:20 ` Abhishek Sahu
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