Re: [PATCH 3/3] soundwire: bus: clear parity interrupt before the mask is enabled

From: Pierre-Louis Bossart
Date: Mon Feb 01 2021 - 13:32:27 EST



* Set SCP_INT1_MASK register, typically bus clash and
diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index f7ba1a77a1df..c1fdc85d0a74 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -1286,7 +1286,8 @@ static int sdw_master_read_intel_prop(struct sdw_bus *bus)
if (quirk_mask & SDW_INTEL_QUIRK_MASK_BUS_DISABLE)
prop->hw_disabled = true;
- prop->quirks = SDW_MASTER_QUIRKS_CLEAR_INITIAL_CLASH;
+ prop->quirks = SDW_MASTER_QUIRKS_CLEAR_INITIAL_CLASH |
+ SDW_MASTER_QUIRKS_CLEAR_INITIAL_PARITY;

move this to intel patch please..

return 0;
}
diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h
index a2766c3b603d..30415354d419 100644
--- a/include/linux/soundwire/sdw.h
+++ b/include/linux/soundwire/sdw.h
@@ -426,6 +426,7 @@ struct sdw_master_prop {
};
#define SDW_MASTER_QUIRKS_CLEAR_INITIAL_CLASH BIT(0)
+#define SDW_MASTER_QUIRKS_CLEAR_INITIAL_PARITY BIT(1)

Why not add this quirk in patch 1..?

There is an element of history here. We first found out about the bus clash on multiple devices and dealt with a specific bug number. Then we spend weeks on the parity issue on a new platform and ultimately showed we needed a similar work-around.

All these problems are not typical from a user perspective; they appear when loading/unloading modules in loops, at some point it seems some hardware devices don't always reset properly or there's something problematic in power delivery.

I don't think it's an issue if we refactor the code to add the quirks first, and add the intel.c patches later. We probably want 2 intel changes to keep the references to the bugs though and the detailed explanations.

Also add comments about each quirk, hopefully it wont be a big table

Sounds fine.