Re: [PATCH] [v3] mtd: spi-nor: gigadevice: Add support for GD25LQ255E

From: "Michael Walle" <mwalle@kernel.org>
To: <Takahiro.Kuwano@infineon.com>,
	<wuweimin@huaqin.corp-partner.google.com>
Cc: <tudor.ambarus@linaro.org>, <pratyush@kernel.org>,
	<linux-mtd@lists.infradead.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] [v3] mtd: spi-nor: gigadevice: Add support for GD25LQ255E
Date: Mon, 20 Apr 2026 12:44:52 +0200	[thread overview]
Message-ID: <DHXX61QRBDVA.2VIO2J63UKZC3@kernel.org> (raw)
In-Reply-To: <792c09f5ae754bf899693f110ef1dbe0@infineon.com>

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On Mon Apr 20, 2026 at 11:51 AM CEST, Takahiro.Kuwano wrote:
> Hi,
>
>> 
>> On Sat Apr 18, 2026 at 10:42 AM CEST, Weimin Wu wrote:
>> > Add support for the GigaDevice GD25LQ255E (JEDEC ID c8 60 19),
>> > a 256Mbit (32MB) SPI NOR flash chip which supports SFDP.
>> >
>> > The chip supports 4K sector erase, dual read, and quad read modes.
>> >
>> > Link: https://download.gigadevice.com/Datasheet/DS-00562-GD25LQ255E-Rev1.2.pdf
>> 
>> Please move the Link: tag above your SoB line.
>> 
>> ..
>> 
>> > diff --git a/drivers/mtd/spi-nor/gigadevice.c b/drivers/mtd/spi-nor/gigadevice.c
>> > index ef1edd0ad..22a430798 100644
>> > --- a/drivers/mtd/spi-nor/gigadevice.c
>> > +++ b/drivers/mtd/spi-nor/gigadevice.c
>> > @@ -82,6 +82,10 @@ static const struct flash_info gigadevice_nor_parts[] = {
>> >  		.size = SZ_16M,
>> >  		.flags = SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB,
>> >  		.no_sfdp_flags = SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ,
>> > +	}, {
>> > +		/* gd25lb256 */
>> > +		.id = SNOR_ID(0xc8, 0x60, 0x19),
>> > +		.flags = SPI_NOR_HAS_LOCK | SPI_NOR_4BIT_BP | SPI_NOR_HAS_TB | SPI_NOR_TB_SR_BIT6,
>> 
>> Reviewed-by: Michael Walle <mwalle@kernel.org>
>> 
> The datasheet explains (in Table 5) that BP2-BP0 control the length
> of protection area (all, 1/2 ... 1/64, 0) and BP3 controls upper/lower.
> It looks 3 BP and 1 TB so SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB should work.
> BP4 protects top or bottom 4KB to 32KB and current SWP doesn't support
> that protection mechanism, right? Sorry if I missed something...

Ha, you are right, thanks for pointing that out. I actually fell for
the wrong comment and looked at that datasheet in the end.. for
which the flags are correct. And what weird name is that gd25lq255..
Anyway. The ID matches the linked datasheet. So something is wrong
here. Weimin, please test the locking properly and update the
comment as Tudor already pointed out.

Thanks,
-michael

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