From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
In the existing code, the SHIM_SYNC::SYNC_GO bit is set, and the code
waits for it to return to zero.
That second wait part is just wrong: the SYNC_GO bit is *write-only* so
there's no way to know if it's cleared by hardware. The code works
because the value for a read-only bit is zero, but that's really just
luck.
Simplify the sequence to a plain read-modify-write.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Reviewed-by: Rander Wang <rander.wang@xxxxxxxxx>
Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
---
drivers/soundwire/intel.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)
diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index 2c1c905f8889..6fdb10117e59 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -475,7 +475,6 @@ static int intel_shim_sync_go_unlocked(struct sdw_intel *sdw)
{
void __iomem *shim = sdw->link_res->shim;
u32 sync_reg;
- int ret;
/* Read SYNC register */
sync_reg = intel_readl(shim, SDW_SHIM_SYNC);
@@ -487,13 +486,9 @@ static int intel_shim_sync_go_unlocked(struct sdw_intel *sdw)
*/
sync_reg |= SDW_SHIM_SYNC_SYNCGO;
- ret = intel_clear_bit(shim, SDW_SHIM_SYNC, sync_reg,
- SDW_SHIM_SYNC_SYNCGO);
+ intel_writel(shim, SDW_SHIM_SYNC, sync_reg);
- if (ret < 0)
- dev_err(sdw->cdns.dev, "SyncGO clear failed: %d\n", ret);
-
- return ret;
+ return 0;
}
static int intel_shim_sync_go(struct sdw_intel *sdw)
--
2.25.1
