Re: [PATCH v2 2/3] mtd: m25p80: consider max message size in m25p80_read

[Marek Vasut <marek.vasut@xxxxxxxxx>]

On 12/23/2016 10:04 PM, Michal Suchanek wrote:
> Hello,

Hi,

> On 23 December 2016 at 19:53, Marek Vasut <marek.vasut@xxxxxxxxx> wrote:
>> On 12/23/2016 04:33 PM, Cyrille Pitchen wrote:
>>> Le 17/08/2016 à 21:09, Heiner Kallweit a écrit :
>>>> Consider a message size limit when calculating the maximum amount
>>>> of data that can be read.
>>>>
>>>> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
>>>
>>> Applied to git://github.com/spi-nor/linux.git
>>
>> Is that the concensus now that we should fix controller crappiness on
>> driver level ? Or did I miss the point of this patch ?
>>
> 
> In general most controllers do have some limit on the amount of data
> they can transfer at once.

My observations suggest otherwise.

> For some you can apply workaround at controller driver level and for
> some it's not practical.
> 
> Also for some the limit is lower so it is more likely hit.
> 
> I guess you can call controllers that have both of these limitations
> crappy but that's what's in the silicone out there.
> 
> If you have better solution to the problem please share it in detail.

I don't have a solution, but I am quite sure that if we now set a
precedent that each and every device driver should take care of each and
every controller's quirk, we have a lot of unpleasant work ahead
of us and it will be quite the maintanance burden. The separations
between device driver and controller driver has been weakened and I
don't think that's good.

-- 
Best regards,
Marek Vasut
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