Re: [PATCH 07/16] soundwire: cadence: mask Slave interrupt before stopping clock

From: Vinod Koul
Date: Fri Mar 13 2020 - 08:24:50 EST


On 11-03-20, 13:41, Pierre-Louis Bossart wrote:
> Intel QA reported a very rare case, possibly hardware-dependent, where
> a Slave can become UNATTACHED during a clock stop sequence, which
> leads to timeouts and failed suspend sequences.
>
> This patch suppresses the handling of all Slave events while this
> transition happens. The two cases that matter are:
>
> a) alerts: if the Slave wants to signal an alert condition, it can do
> so using the in-band wake, so there's almost no impact with this
> patch.
>
> b) sync loss or imp-def reset: in those cases, bringing back the Slave
> to functional state requires a complete re-enumeration. It's better to
> just ignore this case and restart cleanly, rather than attempt a
> 'clean' suspend.
>
> Validation results show the timeouts no longer visible with this patch.
>
> GitHub issue: https://github.com/thesofproject/linux/issues/1678
> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> ---
> drivers/soundwire/cadence_master.c | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
> index 02f18ce6b7e7..a4ba57f44c1f 100644
> --- a/drivers/soundwire/cadence_master.c
> +++ b/drivers/soundwire/cadence_master.c
> @@ -865,6 +865,24 @@ int sdw_cdns_exit_reset(struct sdw_cdns *cdns)
> }
> EXPORT_SYMBOL(sdw_cdns_exit_reset);
>
> +/**
> + * sdw_cdns_enable_slave_interrupt() - Enable SDW slave interrupts
> + * @cdns: Cadence instance
> + * @state: boolean for true/false
> + */
> +static void cdns_enable_slave_interrupts(struct sdw_cdns *cdns, bool state)

Do you want to rename this as cdns_configure_slave_interrupts, with
argument as enable/disable... ?

--
~Vinod