1. Patchew
  2. linux
  3. View series

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

Thierry Reding posted 1 patch 4 years, 3 months ago 
drivers/mailbox/tegra-hsp.c | 5 +++++
1 file changed, 5 insertions(+)
[PATCH v2] mailbox: tegra-hsp: Flush whole channel
Posted by Thierry Reding 4 years, 3 months ago 
From: Pekka Pessi <ppessi@nvidia.com>

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 <ppessi@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Fixes: 91b1b1c3da8a ("mailbox: tegra-hsp: Add support for shared mailboxes")
Cc: stable@vger.kernel.org
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
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
Re: [PATCH v2] mailbox: tegra-hsp: Flush whole channel
Posted by Jon Hunter 4 years, 3 months ago 
Hi Jassi,

On 02/03/2022 15:04, Thierry Reding wrote:
> From: Pekka Pessi <ppessi@nvidia.com>
> 
> 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 <ppessi@nvidia.com>
> Tested-by: Jon Hunter <jonathanh@nvidia.com>
> Fixes: 91b1b1c3da8a ("mailbox: tegra-hsp: Add support for shared mailboxes")
> Cc: stable@vger.kernel.org
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
> 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
Re: [PATCH v2] mailbox: tegra-hsp: Flush whole channel
Posted by Jon Hunter 4 years, 3 months ago 

On 10/03/2022 16:51, Jon Hunter wrote:
> Hi Jassi,
> 
> On 02/03/2022 15:04, Thierry Reding wrote:
>> From: Pekka Pessi <ppessi@nvidia.com>
>>
>> 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 <ppessi@nvidia.com>
>> Tested-by: Jon Hunter <jonathanh@nvidia.com>
>> Fixes: 91b1b1c3da8a ("mailbox: tegra-hsp: Add support for shared 
>> mailboxes")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Thierry Reding <treding@nvidia.com>
>> ---
>> 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 <jonathanh@nvidia.com>

Jon

-- 
nvpublic
Re: [PATCH v2] mailbox: tegra-hsp: Flush whole channel
Posted by Jon Hunter 4 years, 3 months ago 
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 <ppessi@nvidia.com>
>>>
>>> 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 <ppessi@nvidia.com>
>>> Tested-by: Jon Hunter <jonathanh@nvidia.com>
>>> Fixes: 91b1b1c3da8a ("mailbox: tegra-hsp: Add support for shared 
>>> mailboxes")
>>> Cc: stable@vger.kernel.org
>>> Signed-off-by: Thierry Reding <treding@nvidia.com>
>>> ---
>>> 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 <jonathanh@nvidia.com>
Any feedback?

Jon

-- 
nvpublic
Re: [PATCH v2] mailbox: tegra-hsp: Flush whole channel
Posted by Jassi Brar 4 years, 3 months ago 
On Tue, Mar 22, 2022 at 1:29 PM Jon Hunter <jonathanh@nvidia.com> wrote:
>
> Jassi,
> >
> > Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
> Any feedback?
>
https://git.linaro.org/landing-teams/working/fujitsu/integration.git/commit/?h=mailbox-for-next&id=60de2d2dc284e0dd1c2c897d08625bde24ef3454

thnx

Patchew 2.1-devel-ea86937

© 2016 - 2026 Red Hat, Inc.