Re: [PATCH] mtd: spi-nor: Fix quad-enable for flashes with QER bit in SR1

["Michael Walle" <mwalle@kernel.org>]

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On Fri Sep 11, 2026 at 12:33 PM CEST, Jon Hunter wrote:
>
> On 11/09/2026 09:55, Miquel Raynal wrote:
>> Some flashes (eg. from Macronix) do set BFPT_DWORD15_QER_SR1_BIT6, which
>> means they do not have an SR2 to read from/write to. The new generic QE
>> helper was supposed to accommodate this situation but in the last version
>> that got merged, parts of that specific handling has been moved to a
>> more contained location, swp.c (which needed most of the extra code),
>> yet the Macronix case has been forgotten about in that generic QE
>> handling helper. Booting with such flashes will always fail probing.
>> 
>> Fix the situation by making sure we do not attempt to read SR2 if the QE
>> bit is in SR1.
>> 
>> Reported-by: Jon Hunter <jonathanh@nvidia.com>
>> Closes: https://lore.kernel.org/linux-mtd/178876719232.3543902.14451625037676421254.b4-ty@b4/T/#m5bc4ba6776436f2870ced0eb5789d229037ad840
>> Fixes: 63489002d397 ("mtd: spi-nor: Refactor Read Status/Write Status support")
>> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
>> ---
>>   drivers/mtd/spi-nor/core.c | 5 ++++-
>>   1 file changed, 4 insertions(+), 1 deletion(-)
>> 
>> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
>> index e2b6efafdd8d..ac909dfb9657 100644
>> --- a/drivers/mtd/spi-nor/core.c
>> +++ b/drivers/mtd/spi-nor/core.c
>> @@ -985,7 +985,10 @@ static int spi_nor_generic_quad_enable(struct spi_nor *nor)
>>   	if (!qe_mask[0] && !qe_mask[1])
>>   		return 0;
>>   
>> -	ret = spi_nor_read_sr1_and_sr2(nor, sr);
>> +	if (qe_mask[0])
>> +		ret = spi_nor_read_sr1(nor, sr);
>> +	else
>> +		ret = spi_nor_read_sr1_and_sr2(nor, sr);
>>   	if (ret)
>>   		return ret;
>
> I know that there is still some discussion going on about this
> patch, but FWIW this does fix the issue I was seeing.

Thanks, could you give the new version [1] a quick test and a
Tested-by tag?

-michael

[1] https://lore.kernel.org/r/20260911-perso-fix-spi-nor-qe-mxic-v2-1-70c324e9f30e@bootlin.com/

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