From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
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@linux.intel.com Reviewed-by: Rander Wang rander.wang@intel.com Signed-off-by: Bard Liao yung-chuan.liao@linux.intel.com --- 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)