Messages in this thread | | | Date | Sat, 4 Mar 2023 17:49:44 +0800 | Subject | Re: [PATCH 1/2] mailbox: pcc: Add processing platform notification for slave subspaces | From | "lihuisong (C)" <> |
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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. > > .
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