lkml.org 
[lkml]   [2023]   [Mar]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH 1/2] mailbox: pcc: Add processing platform notification for slave subspaces
From

在 2023/3/3 19:07, Sudeep Holla 写道:
> On Fri, Mar 03, 2023 at 09:50:00AM +0800, lihuisong (C) wrote:
>> 在 2023/3/2 21:52, Sudeep Holla 写道:
>>> On Thu, Mar 02, 2023 at 09:57:35AM +0800, lihuisong (C) wrote:
>>>> 在 2023/3/1 21:24, Sudeep Holla 写道:
>>> [...]
>>>
>>>>> +static bool pcc_mbox_cmd_complete_check(struct pcc_chan_info *pchan)
>>>>> +{
>>>>> + u64 val;
>>>>> + int ret;
>>>>> +
>>>>> + ret = pcc_chan_reg_read(&pchan->cmd_complete, &val);
>>>>> + if (ret)
>>>>> + return false;
>>>>> +
>>>> we indeed already check if cmd_complete register is exist.
>>>> IMO, it can simply the code logic and reduce the risk of problems if we
>>>> return true here for the type without this register.
>>>> what do you think?
>>>>
>>> IIUC, your concern is about returning true for type 4 when the register
>>> doesn't exist, right ?
>> Return true in advance for the type without the cmd_complete register.
>> If support the register, we judge if the channel should respond the
>> interrupt based on the value of cmd_complete, like bellow.
> Right, sorry for missing that.
>
>> -->8
>> +static bool pcc_mbox_cmd_complete_check(struct pcc_chan_info *pchan)
>> +{
>> +       u64 val;
>> +       int ret;
>> +
>> +       ret = pcc_chan_reg_read(&pchan->cmd_complete, &val);
>> +       if (ret)
>> +               return false;
>> +
>> +        if (!pchan->cmd_complete.gas)
>> +                return true;
>> +
> Yes we need the above check.
>
>> +       /*
>> +         * Judge if the channel respond the interrupt based on the value of
>> +         * command complete.
>> +         */
>> +       val &= pchan->cmd_complete.status_mask;
>> +       /*
>> +        * If this is PCC slave subspace channel, then the command complete
>> +        * bit 0 indicates that Platform is sending a notification and OSPM
>> +        * needs to respond this interrupt to process this command.
>> +        */
>> +       if (pchan->type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE)
>> +               return !val;
>> +       else
>> +               return !!val;
>> +}
>>> I am saying it won't happen as we bail out if there is no GAS register
>>> from pcc_chan_reg_init(). Or am I missing something here ?
>> Yes, what you say is also ok. Just wondering if it is better to simply the
>> logic.
> Understood now.
>
>>>>> + val &= pchan->cmd_complete.status_mask;
>>>>> +
>>>>> + /*
>>>>> + * If this is PCC slave subspace channel, then the command complete
>>>>> + * bit 0 indicates that Platform is sending a notification and OSPM
>>>>> + * needs to respond this interrupt to process this command.
>>>>> + */
>>>>> + if (pchan->type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE)
>>>>> + return !val;
>>>>> + else
>>>>> + return !!val;
>>>> This else branch is not applicable to type 3. type 3 will cannot respond
>>>> interrupt.
>>> Sorry I don't understand what you mean by that.
>> Sorry for my mistake.
>> I meant that the type2 channel always return false in this function and
>> never respond the interrupt if no check for the GAS register.
>> Because the 'val' for the type without the register is zero.
> Agreed as mentioned above, we need to bail out with true return if no GAS is
> found.
>
Ok, I will fix it as mentioned above.
>
> .

\
 
 \ /
  Last update: 2023-03-27 00:44    [W:0.282 / U:0.176 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site