diff options
| author | Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> | 2020-03-17 11:33:19 -0500 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2020-03-19 12:43:04 +0530 |
| commit | af4cc917826fd1fb5c84a2a0f675777920db9074 (patch) | |
| tree | 487230b80b9d804beb6f4682d9e271c9b698606e /drivers/soundwire | |
| parent | 0d667d01c40b2cb9141108951890b9b27ea32584 (diff) | |
soundwire: cadence: mask Slave interrupt before stopping clock
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@linux.intel.com>
Link: https://lore.kernel.org/r/20200317163329.25501-8-pierre-louis.bossart@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/soundwire')
| -rw-r--r-- | drivers/soundwire/cadence_master.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 37e16199933c..613c63359413 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -866,6 +866,24 @@ 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) +{ + u32 mask; + + mask = cdns_readl(cdns, CDNS_MCP_INTMASK); + if (state) + mask |= CDNS_MCP_INT_SLAVE_MASK; + else + mask &= ~CDNS_MCP_INT_SLAVE_MASK; + + cdns_writel(cdns, CDNS_MCP_INTMASK, mask); +} + +/** * sdw_cdns_enable_interrupt() - Enable SDW interrupts * @cdns: Cadence instance * @state: True if we are trying to enable interrupt. @@ -1263,6 +1281,13 @@ int sdw_cdns_clock_stop(struct sdw_cdns *cdns, bool block_wake) } /* + * Before entering clock stop we mask the Slave + * interrupts. This helps avoid having to deal with e.g. a + * Slave becoming UNATTACHED while the clock is being stopped + */ + cdns_enable_slave_interrupts(cdns, false); + + /* * For specific platforms, it is required to be able to put * master into a state in which it ignores wake-up trials * in clock stop state @@ -1339,6 +1364,9 @@ int sdw_cdns_clock_restart(struct sdw_cdns *cdns, bool bus_reset) { int ret; + /* unmask Slave interrupts that were masked when stopping the clock */ + cdns_enable_slave_interrupts(cdns, true); + ret = cdns_clear_bit(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_CLK_STOP_CLR); if (ret < 0) { |