Re: [PATCH v13 3/5] soc: qcom: rpmh: Invalidate SLEEP and WAKE TCSes before flushing new data

From: Maulik Shah
Date: Tue Mar 10 2020 - 07:10:04 EST



On 3/10/2020 5:12 AM, Doug Anderson wrote:
> Hi,
>
> On Mon, Mar 9, 2020 at 2:31 AM Maulik Shah <mkshah@xxxxxxxxxxxxxx> wrote:
>> TCSes have previously programmed data when rpmh_flush is called.
>> This can cause old data to trigger along with newly flushed.
>>
>> Fix this by cleaning SLEEP and WAKE TCSes before new data is flushed.
>>
>> With this there is no need to invoke rpmh_rsc_invalidate() call from
>> rpmh_invalidate().
>>
>> Simplify rpmh_invalidate() by moving invalidate_batch() inside.
>>
>> Fixes: 600513dfeef3 ("drivers: qcom: rpmh: cache sleep/wake state requests")
>> Signed-off-by: Maulik Shah <mkshah@xxxxxxxxxxxxxx>
>> ---
>> drivers/soc/qcom/rpmh.c | 36 +++++++++++++++---------------------
>> 1 file changed, 15 insertions(+), 21 deletions(-)
>>
>> diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
>> index 03630ae..5bed8f4 100644
>> --- a/drivers/soc/qcom/rpmh.c
>> +++ b/drivers/soc/qcom/rpmh.c
>> @@ -317,19 +317,6 @@ static int flush_batch(struct rpmh_ctrlr *ctrlr)
>> return ret;
>> }
>>
>> -static void invalidate_batch(struct rpmh_ctrlr *ctrlr)
>> -{
>> - struct batch_cache_req *req, *tmp;
>> - unsigned long flags;
>> -
>> - spin_lock_irqsave(&ctrlr->cache_lock, flags);
>> - list_for_each_entry_safe(req, tmp, &ctrlr->batch_cache, list)
>> - kfree(req);
>> - INIT_LIST_HEAD(&ctrlr->batch_cache);
>> - ctrlr->dirty = true;
>> - spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
>> -}
>> -
>> /**
>> * rpmh_write_batch: Write multiple sets of RPMH commands and wait for the
>> * batch to finish.
>> @@ -467,6 +454,11 @@ int rpmh_flush(struct rpmh_ctrlr *ctrlr)
>> return 0;
>> }
>>
>> + /* Invalidate the TCSes first to avoid stale data */
>> + do {
>> + ret = rpmh_rsc_invalidate(ctrlr_to_drv(ctrlr));
>> + } while (ret == -EAGAIN);
>> +
> You forgot to actually check the return value.
>
> if (ret)
> return ret;
Done.
>
>> /* First flush the cached batch requests */
>> ret = flush_batch(ctrlr);
>> if (ret)
>> @@ -503,19 +495,21 @@ int rpmh_flush(struct rpmh_ctrlr *ctrlr)
>> *
>> * @dev: The device making the request
>> *
>> - * Invalidate the sleep and active values in the TCS blocks.
>> + * Invalidate the sleep and wake values in batch_cache.
> Thanks for updating this. It was on my todo list. Can you also
> update the function description, which still says "Invalidate all
> sleep and active sets sets." While you're at it, remove the double
> "sets".

Done.

Thanks,
Maulik

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