Re: [PATCH 1/3] hwmon: (pmbus) Add driver for Delta DPS-920AB PSU

[Guenter Roeck <linux@roeck-us.net>]

On 5/27/21 12:43 PM, Robert Marko wrote:
> On Thu, May 27, 2021 at 9:27 PM Guenter Roeck <linux@roeck-us.net> wrote:
>>
>> On Thu, May 27, 2021 at 09:14:03PM +0200, Robert Marko wrote:
>>> On Thu, May 27, 2021 at 6:37 PM Guenter Roeck <linux@roeck-us.net> wrote:
>>>>
>>>> On 5/27/21 7:58 AM, Robert Marko wrote:
>>>> [ ... ]
>>>>
>>>>>>>>>> I tried applying the block support for mv64xx as well:
>>>>>>>>>> https://patchwork.ozlabs.org/project/linux-i2c/patch/20200118115820.9080-1-fuga@studiofuga.com/
>>>>>>>>
>>>>>>>> That patch would be needed, but it looks buggy to me. This chunk:
>>>>>>>>
>>>>>>>> +               drv_data->effective_length = data+1;
>>>>>>>> +               drv_data->bytes_left = data+1;
>>>>>>>> +               drv_data->msg->len = data+1;
>>>>>>>>
>>>>>>>> should be:
>>>>>>>>
>>>>>>>> +               drv_data->effective_length = data+1;
>>>>>>>> +               drv_data->bytes_left = data;
>>>>>>>> +               drv_data->msg->len = data+1;
>>>>>>>>
>>>>>>>> It should also make sure that 'data' is not larger than I2C_SMBUS_BLOCK_MAX,
>>>>>>>> and bail out if it isn't.
>>>>>>>
>>>>>>> Yeah, I did not check the contents, I just saw 2 reviews and tested it
>>>>>>> since it can't hurt.
>>>>>>
>>>>>> That patch doesn't work at all. Make the above change, and also change
>>>>>> the type of effective_length from u32 to int, and try again.
>>>>>
>>>>> I was just looking and it, and doing the changes you recommended make
>>>>> no difference at all.
>>>>>
>>>>
>>>> Is the i2c controller compatible with marvell,mv78230-i2c ?
>>>> The block transfers would not work in that case. Let me know
>>>> and I'll send you a patch that might fix it.
>>>
>>> Yes, the CPU is Armada 7040 and I can see that compatible is
>>> marvell,mv78230-i2c indeed.
>>>
>>> It would be great if you have the patch,
>>
>> See below.
> 
> I can confirm that this does indeed enable block reads and
> i2c_smbus_read_block_data()
> works now.
> 
> PMBUS_MFR_ID and PMBUS_MFR_MODEL are indeed populated.
> 

Excellent.

Guenter