[LEDE-DEV] [PATCH v4 2/5] linux/mtd: add id for mx25u3235f needed by ZyXEL NBG6817

[Arjen de Korte]

Citeren André Valentin <avalentin at marcant.net>:

> Hi,
>
> Am 25.10.2016 um 08:58 schrieb Arjen de Korte:> Citeren André  
> Valentin <avalentin at marcant.net>:
>>
>>> Signed-off-by: André Valentin <avalentin at marcant.net>
>>> ---
>>>  .../patches-4.4/477-mtd-add-spi-nor-add-mx25u3235f.patch       |  
>>> 10 ++++++++++
>>>  1 file changed, 10 insertions(+)
>>>  create mode 100644  
>>> target/linux/generic/patches-4.4/477-mtd-add-spi-nor-add-mx25u3235f.patch
>>>
>>> diff --git  
>>> a/target/linux/generic/patches-4.4/477-mtd-add-spi-nor-add-mx25u3235f.patch  
>>> b/target/linux/generic/patches-4.4/477-mtd-add-spi-nor-add-mx25u3235f.patch
>>> new file mode 100644
>>> index 0000000..45533e1
>>> --- /dev/null
>>> +++  
>>> b/target/linux/generic/patches-4.4/477-mtd-add-spi-nor-add-mx25u3235f.patch
>>> @@ -0,0 +1,10 @@
>>> +--- a/drivers/mtd/spi-nor/spi-nor.c    2016-10-09 00:34:19.206155838 +0200
>>> ++++ b/drivers/mtd/spi-nor/spi-nor.c    2016-10-09 00:37:11.048495602 +0200
>>> +@@ -721,6 +721,7 @@ static const struct flash_info spi_nor_i
>>> +     { "mx25l3205d",  INFO(0xc22016, 0, 64 * 1024,  64, SECT_4K) },
>>> +     { "mx25l3255e",  INFO(0xc29e16, 0, 64 * 1024,  64, SECT_4K) },
>>> +     { "mx25l6405d",  INFO(0xc22017, 0, 64 * 1024, 128, SECT_4K) },
>>> ++    { "mx25u3235f",     INFO(0xc22536, 0, 64 * 1024, 64, 0) },
>>
>> Are you sure the above is correct? According to the datasheet, this  
>> device does support both 4K and 64K erase size.
>
> I'm not 100% sure. I got the specs from another patch used in zyxel sources.
> Should I change it to SECT_4K?

To be honest, I don't know. There may be reasons not to use 4K erase  
size (erasing 16 x 4K is usually much slower than erasing a block of  
64K), but there may also be reasons to do so (it may be more efficient  
if a flash filesystem can use smaller blocks). I did notice that for  
the mx25l12805d and mx25l12855e, 4K erase size is supported by the  
device but also not mentioned in this table.