linux-mtd.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: <Tudor.Ambarus@microchip.com>
To: <michael@walle.cc>
Cc: <p.yadav@ti.com>, <miquel.raynal@bootlin.com>, <richard@nod.at>,
	<vigneshr@ti.com>, <linux-mtd@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] mtd: spi-nor: introduce SNOR_ID3()
Date: Tue, 19 Jul 2022 07:33:26 +0000	[thread overview]
Message-ID: <7365146d-b001-2a14-014d-62a6b19f4381@microchip.com> (raw)
In-Reply-To: <02125e047cfbf347d81811224be3141e@walle.cc>

On 7/19/22 10:07, Michael Walle wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> Am 2022-07-19 07:57, schrieb Tudor.Ambarus@microchip.com:
>> On 5/10/22 17:02, Michael Walle wrote:
>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know
>>> the content is safe
>>>
>>> Up until now, flashes were defined by specifying the JEDEC ID, the
>>> sector size and the number of sectors. This can be read by parsing the
>>> SFDP, we don't have to specify it. Thus provide a new macro SNOR_ID3()
>>> which just takes the JEDEC ID and implicitly set .parse_sfdp = true.
>>> All
>>> new flashes which have SFDP should use this macro.
>>
>> I like the idea, but you need to refine it a bit.
>> Your assumptions are true only for flashes that are compliant with SFDP
>> revB or
>> later because params->page_size is initialized by querying BFPT DWORD
>> 11. I think it would be good to specify this in the comment section.
> 
> Sure.
> 
>> Also, I think you introduce
>> a bug in spi_nor_select_erase() when CONFIG_MTD_SPI_NOR_USE_4K_SECTORS
>> is not
>> selected. wanted_size will be zero, will you select an invalid erase
>> type?
> 
> You mean to squeeze [1] into this one? If so, sure.
> 
> -michael
> 
> [1]
> https://lore.kernel.org/linux-mtd/20220716000643.3541839-1-quic_jaehyoo@quicinc.com/

No, these are orthogonal. If you keep wanted_size to zero, then
spi_nor_select_uniform_erase() will return NULL, doesn't it?


Maybe to adapt the code to something like
diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 21cefe2864ba..dd6cd852d1ef 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -2148,7 +2148,7 @@ static int spi_nor_select_erase(struct spi_nor *nor)
        struct spi_nor_erase_map *map = &nor->params->erase_map;
        const struct spi_nor_erase_type *erase = NULL;
        struct mtd_info *mtd = &nor->mtd;
-       u32 wanted_size = nor->info->sector_size;
+       u32 wanted_size = nor->params->sector_size;

and fill nor->params->sector_size even when no SFDP

Also, params->size = (u64)info->sector_size * info->n_sectors; from
spi_nor_init_default_params() becomes superfluous. I would check
the fields that I don't initialize in flash_info with SNOR_ID3
and check how I can mitigate their absence throughout the code.
______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

  reply	other threads:[~2022-07-19  7:33 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-10 14:02 [PATCH 0/2] introduce SNOR_ID3() Michael Walle
2022-05-10 14:02 ` [PATCH 1/2] mtd: spi-nor: " Michael Walle
2022-06-05 15:00   ` Tom Fitzhenry
2022-07-12  7:23   ` Pratyush Yadav
2022-07-15 12:19     ` Biju Das
2022-07-19  5:57   ` Tudor.Ambarus
2022-07-19  7:07     ` Michael Walle
2022-07-19  7:33       ` Tudor.Ambarus [this message]
2022-07-19  7:57         ` Michael Walle
2022-07-19  8:30           ` Tudor.Ambarus
2022-07-28  3:24     ` Tudor.Ambarus
2022-07-28 13:12       ` Michael Walle
2022-07-28 13:31         ` Tudor.Ambarus
2022-07-28 13:56           ` Michael Walle
2022-05-10 14:02 ` [PATCH 2/2] mtd: spi-nor: winbond: use SNOR_ID3() for w25q512nwm Michael Walle
2022-07-12  8:40   ` Tudor.Ambarus
2022-07-18  7:21     ` Michael Walle
2022-07-18  7:25     ` Michael Walle
2022-07-19  6:00       ` Tudor.Ambarus
2022-07-19  7:02         ` Michael Walle
2022-07-19  7:24           ` Tudor.Ambarus
2022-05-10 14:03 ` [PATCH 0/2] mtd: spi-nor: introduce SNOR_ID3() Michael Walle

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=7365146d-b001-2a14-014d-62a6b19f4381@microchip.com \
    --to=tudor.ambarus@microchip.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mtd@lists.infradead.org \
    --cc=michael@walle.cc \
    --cc=miquel.raynal@bootlin.com \
    --cc=p.yadav@ti.com \
    --cc=richard@nod.at \
    --cc=vigneshr@ti.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).