2022-03-03 00:16:20

by Thierry Reding

[permalink] [raw]
Subject: [PATCH v2] mailbox: tegra-hsp: Flush whole channel

From: Pekka Pessi <[email protected]>

The txdone can re-fill the mailbox. Keep polling the mailbox during the
flush until all the messages have been delivered.

This fixes an issue with the Tegra Combined UART (TCU) where output can
get truncated under high traffic load.

Signed-off-by: Pekka Pessi <[email protected]>
Tested-by: Jon Hunter <[email protected]>
Fixes: 91b1b1c3da8a ("mailbox: tegra-hsp: Add support for shared mailboxes")
Cc: [email protected]
Signed-off-by: Thierry Reding <[email protected]>
---
Changes in v2:
- add Fixes: line
- Cc stable

drivers/mailbox/tegra-hsp.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c
index acd0675da681..78f7265039c6 100644
--- a/drivers/mailbox/tegra-hsp.c
+++ b/drivers/mailbox/tegra-hsp.c
@@ -412,6 +412,11 @@ static int tegra_hsp_mailbox_flush(struct mbox_chan *chan,
value = tegra_hsp_channel_readl(ch, HSP_SM_SHRD_MBOX);
if ((value & HSP_SM_SHRD_MBOX_FULL) == 0) {
mbox_chan_txdone(chan, 0);
+
+ /* Wait until channel is empty */
+ if (chan->active_req != NULL)
+ continue;
+
return 0;
}

--
2.35.1


2022-03-10 19:07:15

by Jon Hunter

[permalink] [raw]
Subject: Re: [PATCH v2] mailbox: tegra-hsp: Flush whole channel

Hi Jassi,

On 02/03/2022 15:04, Thierry Reding wrote:
> From: Pekka Pessi <[email protected]>
>
> The txdone can re-fill the mailbox. Keep polling the mailbox during the
> flush until all the messages have been delivered.
>
> This fixes an issue with the Tegra Combined UART (TCU) where output can
> get truncated under high traffic load.
>
> Signed-off-by: Pekka Pessi <[email protected]>
> Tested-by: Jon Hunter <[email protected]>
> Fixes: 91b1b1c3da8a ("mailbox: tegra-hsp: Add support for shared mailboxes")
> Cc: [email protected]
> Signed-off-by: Thierry Reding <[email protected]>
> ---
> Changes in v2:
> - add Fixes: line
> - Cc stable
>
> drivers/mailbox/tegra-hsp.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c
> index acd0675da681..78f7265039c6 100644
> --- a/drivers/mailbox/tegra-hsp.c
> +++ b/drivers/mailbox/tegra-hsp.c
> @@ -412,6 +412,11 @@ static int tegra_hsp_mailbox_flush(struct mbox_chan *chan,
> value = tegra_hsp_channel_readl(ch, HSP_SM_SHRD_MBOX);
> if ((value & HSP_SM_SHRD_MBOX_FULL) == 0) {
> mbox_chan_txdone(chan, 0);
> +
> + /* Wait until channel is empty */
> + if (chan->active_req != NULL)
> + continue;
> +
> return 0;
> }
>


Any feedback on this? Can we queue this up for v5.18?

Thanks
Jon

--
nvpublic

2022-03-10 19:27:22

by Jon Hunter

[permalink] [raw]
Subject: Re: [PATCH v2] mailbox: tegra-hsp: Flush whole channel



On 10/03/2022 16:51, Jon Hunter wrote:
> Hi Jassi,
>
> On 02/03/2022 15:04, Thierry Reding wrote:
>> From: Pekka Pessi <[email protected]>
>>
>> The txdone can re-fill the mailbox. Keep polling the mailbox during the
>> flush until all the messages have been delivered.
>>
>> This fixes an issue with the Tegra Combined UART (TCU) where output can
>> get truncated under high traffic load.
>>
>> Signed-off-by: Pekka Pessi <[email protected]>
>> Tested-by: Jon Hunter <[email protected]>
>> Fixes: 91b1b1c3da8a ("mailbox: tegra-hsp: Add support for shared
>> mailboxes")
>> Cc: [email protected]
>> Signed-off-by: Thierry Reding <[email protected]>
>> ---
>> Changes in v2:
>> - add Fixes: line
>> - Cc stable
>>
>>   drivers/mailbox/tegra-hsp.c | 5 +++++
>>   1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c
>> index acd0675da681..78f7265039c6 100644
>> --- a/drivers/mailbox/tegra-hsp.c
>> +++ b/drivers/mailbox/tegra-hsp.c
>> @@ -412,6 +412,11 @@ static int tegra_hsp_mailbox_flush(struct
>> mbox_chan *chan,
>>           value = tegra_hsp_channel_readl(ch, HSP_SM_SHRD_MBOX);
>>           if ((value & HSP_SM_SHRD_MBOX_FULL) == 0) {
>>               mbox_chan_txdone(chan, 0);
>> +
>> +            /* Wait until channel is empty */
>> +            if (chan->active_req != NULL)
>> +                continue;
>> +
>>               return 0;
>>           }
>
>
> Any feedback on this? Can we queue this up for v5.18?

Feel free to add my ...

Reviewed-by: Jon Hunter <[email protected]>

Jon

--
nvpublic

2022-03-23 00:52:50

by Jon Hunter

[permalink] [raw]
Subject: Re: [PATCH v2] mailbox: tegra-hsp: Flush whole channel

Jassi,

On 10/03/2022 17:37, Jon Hunter wrote:
>
>
> On 10/03/2022 16:51, Jon Hunter wrote:
>> Hi Jassi,
>>
>> On 02/03/2022 15:04, Thierry Reding wrote:
>>> From: Pekka Pessi <[email protected]>
>>>
>>> The txdone can re-fill the mailbox. Keep polling the mailbox during the
>>> flush until all the messages have been delivered.
>>>
>>> This fixes an issue with the Tegra Combined UART (TCU) where output can
>>> get truncated under high traffic load.
>>>
>>> Signed-off-by: Pekka Pessi <[email protected]>
>>> Tested-by: Jon Hunter <[email protected]>
>>> Fixes: 91b1b1c3da8a ("mailbox: tegra-hsp: Add support for shared
>>> mailboxes")
>>> Cc: [email protected]
>>> Signed-off-by: Thierry Reding <[email protected]>
>>> ---
>>> Changes in v2:
>>> - add Fixes: line
>>> - Cc stable
>>>
>>>   drivers/mailbox/tegra-hsp.c | 5 +++++
>>>   1 file changed, 5 insertions(+)
>>>
>>> diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c
>>> index acd0675da681..78f7265039c6 100644
>>> --- a/drivers/mailbox/tegra-hsp.c
>>> +++ b/drivers/mailbox/tegra-hsp.c
>>> @@ -412,6 +412,11 @@ static int tegra_hsp_mailbox_flush(struct
>>> mbox_chan *chan,
>>>           value = tegra_hsp_channel_readl(ch, HSP_SM_SHRD_MBOX);
>>>           if ((value & HSP_SM_SHRD_MBOX_FULL) == 0) {
>>>               mbox_chan_txdone(chan, 0);
>>> +
>>> +            /* Wait until channel is empty */
>>> +            if (chan->active_req != NULL)
>>> +                continue;
>>> +
>>>               return 0;
>>>           }
>>
>>
>> Any feedback on this? Can we queue this up for v5.18?
>
> Feel free to add my ...
>
> Reviewed-by: Jon Hunter <[email protected]>
Any feedback?

Jon

--
nvpublic