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

[Jon Hunter]

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

Jon

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