On 08/01/2017 12:20 AM, Alexandru Gagniuc wrote:
> On 07/31/2017 02:33 PM, Marek Vasut wrote:
>> On 07/31/2017 07:17 PM, Alexandru Gagniuc wrote:
>
> Hi Marek,
>
> Thank you again for your feedback. I've applied a majority of your
> suggestions, and I am very happy with the result. I should have v2
> posted within a day or so.
No. You should have v2 out in about a week or so after people have time
to review v1 some more.
> [snip]
>>>>> +/*
>>>>> + * This mask does not match reality. Get over it:
>>>>
>>>> What is this about ?
>>>
>>> Each stage of the QSPI chain has two registers. The second register has
>>> a bitfield which takes in the length of the stage. For example, for
>>> DATA2, we can set the length up to 0x4000, but for ADDR2, we can only
>>> set a max of 4 bytes. I wrote this comment as a reminder to myself to be
>>> careful about using this mask. I'll rephrase the comment for [v2]
>>
>> Please do.
>>
> Staged for [PATCH v2]
>
>>>>> + * DATA2: 0x3fff
>>>>> + * CMD2: 0x0003
>>>>> + * ADDR2: 0x0007
>>>>> + * PERF2: 0x0000
>>>>> + * HI_Z: 0x003f
>>>>> + * BCNT: 0x0007
>>>>> + */
>>>>> +#define CHAIN_LEN(x) ((x - 1) & ASPI_DATA_LEN_MASK)
btw parenthesis around (x) missing, although this is like GEN_MASK() or
something here ...
>>>>> +struct anarion_qspi {
>>>>> + struct spi_nor nor;
>>>>> + struct device *dev;
>>>>> + uintptr_t regbase;
>>>>
>>>> Should be void __iomem * I guess ?
>>>
>>> I chose uintptr_t as opposed to void *, because arithmetic on void * is
>>> not valid in C. What is the right answer hen, without risking undefined
>>> behavior?
>>
>> What sort of arithmetic ? It's perfectly valid in general ...
>
> ISO/IEC 9899:201x, Section 6.5.6, constraint(2) is not met when the one
> of the operands to addition is a void pointer.
> Section 6.2.5 (19) defines void to be an incomplete type.
Is that something new in C 201x draft ? Anyway, this would mean half of
the drivers are broken, so I'm not convinced.
> [snip]
>
>>>> Is this stuff below something like ioread32_rep() ?
>>>>
>>>>> + aspi_write_reg(aspi, ASPI_REG_BYTE_COUNT, sizeof(uint32_t));
>>>>> + while (len >= 4) {
>>>>> + data = aspi_read_reg(aspi, ASPI_REG_DATA1);
>>>>> + memcpy(buf, &data, sizeof(data));
>>>>> + buf += 4;
>>>>> + len -= 4;
>>>>> + }
>>>
>>> That is very similar to ioread32_rep, yes. I kept this as for the
>>> reasons outlined above, but changing this to _rep() seems innocent
>>> enough.
>>
>> What reason ?
>
> Being able to share the code between the different codebases where it is
> used.
Yes, that argument isn't gonna work, it'd make things impossible to
maintain in the kernel.
--
Best regards,
Marek Vasut
