Re: [PATCH RESEND v5 3/3] mtd: spinand: repeat reading in regular mode if continuous reading fails

[Mikhail Kshevetskiy]

Hi Miquel,
I think spi-mem capability for continuous read support is the best
solution.

On 10/29/26 18:58, Miquel Raynal wrote:
> Hi Mikhail,
>
> On 18/09/2025 at 00:54:01 +03, Mikhail Kshevetskiy <mikhail.kshevetskiy@xxxxxxxxx> wrote:
>
>> Continuous reading may result in multiple flash pages reading in one
>> operation. Unfortunately, not all spinand controllers support such
>> large reading. They will read less data. Unfortunately, the operation
>> can't be continued.
>>
>> In this case:
>>  * disable continuous reading on this (not good enough) spi controller
>>  * repeat reading in regular mode.
>>
>> Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@xxxxxxxxx>
> This patch unfortunately breaks continuous reads on my boards without
> dirmap support. The fact that they do not have dirmap support does not
> mean they are not capable of keeping CS asserted, these are two
> orthogonal hardware capabilities and it seems that we cannot easily
> discover it at run time.
>
> I recently had a similar issue with a "powerful" controller
> (cadence-qspi) with dirmap support. The fact that controllers will or
> will not spuriously assert their chip select is not discoverable
> either. As a result I created a spi-mem capability to flag this
> impossibility, which disables continuous reads. I will send a patch to
> revert this commit (keeping the previous ones) and another one to flag
> the Airoha controller as not having full control over its CS.
>
> Thanks,
> Miquèl