[BUG] pxa3xx: wait time out when scanning for bb

[Ezequiel Garcia]

On 11 December 2017 at 10:13, Miquel RAYNAL
<miquel.raynal at free-electrons.com> wrote:
> On Mon, 11 Dec 2017 09:30:53 -0300
> Ezequiel Garcia <ezequiel at vanguardiasur.com.ar> wrote:
>
>> On 10 December 2017 at 11:17, Miquel RAYNAL
>> <miquel.raynal at free-electrons.com> wrote:
>> > Hi Ezequiel,
>> >
>> >> >> [    2.296924] nand: device found, Manufacturer ID: 0x2c, Chip
>> >> >> ID: 0xda [    2.303311] nand: Micron MT29F2G08ABAEAH4
>> >> >> [    2.307334] nand: 256 MiB, SLC, erase size: 128 KiB, page
>> >> >> size: 2048, OOB size: 64
>> >> >> [    2.314939] pxa3xx-nand f10d0000.flash: ECC strength 16, ECC
>> >> >> step size 2048
>> >> >
>> >> > In theory, Marvell NAND flash controller does support 16-bit
>> >> > strength per 512 bytes over 2048 bytes pages. However, this
>> >> > controller driver (pxa3xx_nand) does not. See [1] for the
>> >> > supported configurations.
>> >>
>> >> Why do you say the driver does not support it?
>> >
>> > My reading of the trace was incomplete as it is mentioned that the
>> > 16-bit correction applies on 2kiB chunks (a full page) while I was
>> > referring to 512 bytes chunks.
>> >
>> > Protecting 2kiB pages with BCH algorithm may prevent the flip of up
>> > to 16 bits per page, which may also be seen as 4 bits per 512 bytes.
>> > Asking for 16-bit strength for 512 bytes (configuration I was
>> > referring to) is supported by the controller but simply not
>> > implemented.
>> >
>> > However, below code setting up ecc->strength to 16 while
>> > ecc_stepsize is 512 is, IMHO, wrong.
>> >
>>
>> If you feel there's anything wrong and worth changing in the current
>> driver, please submit a patch.
>
> Somehow I did it last week, by sending the first version of a rework :)
>

Sure, and I'm happy to see the rework.

However, this driver will still be around, possibly for many years
given vendors using stable kernels.

So, really: if there's anything you think is worth discussing and fixing,
please submit a patch.

Thanks!
-- 
Ezequiel García, VanguardiaSur
www.vanguardiasur.com.ar