Re: [PATCH v2] mtd: spi-nor: Add support for N25Q256A13 as N25Q256A

[Marek Vasut <marek.vasut@gmail.com>]

On 01/30/2017 02:29 PM, Cyrille Pitchen wrote:
> Hi Nobuhiro,
> 
> Le 27/01/2017 à 02:51, Nobuhiro Iwamatsu a écrit :
>> Add new Micron N25Q256A (N25Q256A13) 256Mbit NOR Flash in the list
>> of supported devices. This chip has the same structure as the N25Q256A
>> but ID is different. And this fixes N25Q256A to N25Q256 to fit chip
>> name to other n25q chip names.
>>
>> Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.kw@hitachi.com>
>> CC: Jagan Teki <jagan@openedev.com>
>> CC: Marek Vasut <marek.vasut@gmail.com>
>> ---
>>  drivers/mtd/spi-nor/spi-nor.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
>> index da7cd69d4857..a2a6922e356f 100644
>> --- a/drivers/mtd/spi-nor/spi-nor.c
>> +++ b/drivers/mtd/spi-nor/spi-nor.c
>> @@ -887,7 +887,8 @@ static const struct flash_info spi_nor_ids[] = {
>>  	{ "n25q064a",    INFO(0x20bb17, 0, 64 * 1024,  128, SECT_4K | SPI_NOR_QUAD_READ) },
>>  	{ "n25q128a11",  INFO(0x20bb18, 0, 64 * 1024,  256, SECT_4K | SPI_NOR_QUAD_READ) },
>>  	{ "n25q128a13",  INFO(0x20ba18, 0, 64 * 1024,  256, SECT_4K | SPI_NOR_QUAD_READ) },
>> -	{ "n25q256a",    INFO(0x20ba19, 0, 64 * 1024,  512, SECT_4K | SPI_NOR_QUAD_READ) },
>> +	{ "n25q256",     INFO(0x20ba19, 0, 64 * 1024,  512, SECT_4K | SPI_NOR_QUAD_READ) },
>> +	{ "n25q256a",    INFO(0x20bb19, 0, 64 * 1024,  512, SECT_4K | SPI_NOR_QUAD_READ) },
> 
> This patch changes the association "n25q256a" <-> 20 ba 19: "n25q256a"
> would be now associated to 20 bb 19.
> However some device trees use the "micron,n25q256a" as compatible string:
> - arch/arm/boot/dts/imx6sx-sbd.dts: compatible = "micron,n25q256a",
> "jedec,spi-nor";
> - arch/arm/boot/dts/socfpga_arria5_socdk.dts: compatible = "n25q256a";
> - arch/arm/boot/dts/socfpga_cyclone5_socrates.dts: compatible = "n25q256a";
> - arch/arm/boot/dts/imx6ul-14x14-evk.dts: compatible = "micron,n25q256a";
> 
> If the actual JEDEC ID read from the Micron SPI memory of one of these
> boards is 20 ba 19 and if you now associate the string "n25q256a" to the
> different JEDEC ID 20 bb 19, then spi_nor_scan() is likely to display the
> warning message during the boot:
> 
> dev_warn(dev, "found %s, expected %s\n", jinfo->name, info->name);
> 
> 
> Displaying such a warning during the boot process would be an unwanted side
> effect of this patch and users may complain or ask why such warning is now
> displayed in the boot log.
> 
> You may create a new entry for the 20 bb 19 JEDEC ID but I don't think it
> is totally safe to remove the old n25q256a entry.

If the old DTs were lazy and are now broken, then I think the warning is
justified ?

-- 
Best regards,
Marek Vasut