linux-kernel - Re: [PATCH v2] remoteproc: qcom_q6v5: Assign mpss region to Q6 before MBA boot

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Message-ID: <474e42a6acb527b4d2bb1004d65ad139@codeaurora.org>
Date:   Thu, 17 Sep 2020 21:29:48 +0530
From:   Sibi Sankar <sibis@...eaurora.org>
To:     Stephen Boyd <swboyd@...omium.org>
Cc:     bjorn.andersson@...aro.org, agross@...nel.org,
        linux-arm-msm@...r.kernel.org, linux-remoteproc@...r.kernel.org,
        linux-kernel@...r.kernel.org, ohad@...ery.com,
        evgreen@...omium.org, linux-arm-msm-owner@...r.kernel.org
Subject: Re: [PATCH v2] remoteproc: qcom_q6v5: Assign mpss region to Q6 before
 MBA boot

Stephen,
Thanks for taking time to review the
series.

On 2020-09-16 22:47, Stephen Boyd wrote:
> Quoting Sibi Sankar (2020-09-16 07:52:52)
>> On secure devices which support warm reset, the MBA firmware requires
>> access to the modem region to clear them out. Hence provide Q6 access
>> to this region before MBA boot. This will be a nop during a modem SSR.
>> 
> 
> Does it need a Fixes: tag? Probably.

it doesn't really fix anything previously
committed. When SC7180 support was added,
mss driver still lacked secure boot support
and when Bjorn added secure boot support,
none of the secure devices necessarily
supported warm reset. So I'll skip adding
fixes tag.

> 
>> Signed-off-by: Sibi Sankar <sibis@...eaurora.org>
>> ---
>> 
> 
> Trivia time!
> 
>> 
>> diff --git a/drivers/remoteproc/qcom_q6v5_mss.c 
>> b/drivers/remoteproc/qcom_q6v5_mss.c
>> index c401bcc263fa..f989ca81d374 100644
>> --- a/drivers/remoteproc/qcom_q6v5_mss.c
>> +++ b/drivers/remoteproc/qcom_q6v5_mss.c
>> @@ -931,6 +931,16 @@ static int q6v5_mba_load(struct q6v5 *qproc)
>>                 goto assert_reset;
>>         }
>> 
>> +       /* Some versions of the MBA firmware will upon boot wipe the 
>> MPSS region as well, so provide
> 
> Should have /* on a line by itself.
> 
>> +        * the Q6 access to this region.
>> +        */
>> +       ret = q6v5_xfer_mem_ownership(qproc, &qproc->mpss_perm, false, 
>> true,
>> +                                     qproc->mpss_phys, 
>> qproc->mpss_size);
>> +       if (ret) {
>> +               dev_err(qproc->dev, "assigning Q6 access to mpss 
>> memory failed: %d\n", ret);
>> +               goto disable_active_clks;
>> +       }
>> +
>>         /* Assign MBA image access in DDR to q6 */
>>         ret = q6v5_xfer_mem_ownership(qproc, &qproc->mba_perm, false, 
>> true,
>>                                       qproc->mba_phys, 
>> qproc->mba_size);
>> @@ -1137,8 +1147,7 @@ static int q6v5_mpss_load(struct q6v5 *qproc)
>> 
>>         /**
> 
> Should be /* instead of /**, the latter is for kernel-doc which this is
> not.

sure I'll get ^^ done in the next
re-spin.

> 
>>          * In case of a modem subsystem restart on secure devices, the 
>> modem
>> -        * memory can be reclaimed only after MBA is loaded. For modem 
>> cold
>> -        * boot this will be a nop
>> +        * memory can be reclaimed only after MBA is loaded.
>>          */
>>         q6v5_xfer_mem_ownership(qproc, &qproc->mpss_perm, true, false,
>>                                 qproc->mpss_phys, qproc->mpss_size);

-- 
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