Add mask to correctly read the SoundWire SHIM LCAP register. Only bits 2..0 are meaningful, the rest is about link synchronization and stream channel mapping. Without this mask, the hardware information would always be larger than whatever the BIOS would report.
Also trap the case with zero links.
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/intel_init.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/soundwire/intel_init.c b/drivers/soundwire/intel_init.c index 771a53a5c033..70637a0383d2 100644 --- a/drivers/soundwire/intel_init.c +++ b/drivers/soundwire/intel_init.c @@ -81,6 +81,7 @@ static struct sdw_intel_ctx
/* Check SNDWLCAP.LCOUNT */ caps = ioread32(res->mmio_base + SDW_SHIM_BASE + SDW_SHIM_LCAP); + caps &= GENMASK(2, 0);
/* Check HW supported vs property value and use min of two */ count = min_t(u8, caps, count); @@ -90,6 +91,9 @@ static struct sdw_intel_ctx dev_err(&adev->dev, "Link count %d exceeds max %d\n", count, SDW_MAX_LINKS); return NULL; + } else if (!count) { + dev_warn(&adev->dev, "No SoundWire links detected\n"); + return NULL; }
dev_dbg(&adev->dev, "Creating %d SDW Link devices\n", count);