soundwire: ignore uniqueID when irrelevant
authorPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Tue, 22 Oct 2019 23:48:08 +0000 (18:48 -0500)
committerVinod Koul <vkoul@kernel.org>
Sat, 9 Nov 2019 11:16:56 +0000 (16:46 +0530)
The uniqueID is useful when there are two or more devices of the same
type (identical manufacturer ID, part ID) on the same link.

When there is a single device of a given type on a link, its uniqueID
is irrelevant. It's not uncommon on actual platforms to see variations
of the uniqueID, or differences between devID registers and ACPI _ADR
fields.

This patch suggests a filter on startup to identify 'single' devices
and tag them accordingly. The uniqueID is then not used for the probe,
and the device name omits the uniqueID as well.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20191022234808.17432-4-pierre-louis.bossart@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
drivers/soundwire/bus.c
drivers/soundwire/slave.c

index fc53dbe57f8545bcad26f84a63bfe57c14e564ed..be5d437058ed198e5d779336a8b73fac737aec28 100644 (file)
@@ -422,10 +422,11 @@ static struct sdw_slave *sdw_get_slave(struct sdw_bus *bus, int i)
 
 static int sdw_compare_devid(struct sdw_slave *slave, struct sdw_slave_id id)
 {
-       if (slave->id.unique_id != id.unique_id ||
-           slave->id.mfg_id != id.mfg_id ||
+       if (slave->id.mfg_id != id.mfg_id ||
            slave->id.part_id != id.part_id ||
-           slave->id.class_id != id.class_id)
+           slave->id.class_id != id.class_id ||
+           (slave->id.unique_id != SDW_IGNORED_UNIQUE_ID &&
+            slave->id.unique_id != id.unique_id))
                return -ENODEV;
 
        return 0;
index e4e4505b5111d186e2d55ea75bde321175a1116b..e656ff57fc042530686b338c35fd0cd036094941 100644 (file)
@@ -29,10 +29,17 @@ static int sdw_slave_add(struct sdw_bus *bus,
        slave->dev.parent = bus->dev;
        slave->dev.fwnode = fwnode;
 
-       /* name shall be sdw:link:mfg:part:class:unique */
-       dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x",
-                    bus->link_id, id->mfg_id, id->part_id,
-                    id->class_id, id->unique_id);
+       if (id->unique_id == SDW_IGNORED_UNIQUE_ID) {
+               /* name shall be sdw:link:mfg:part:class */
+               dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x",
+                            bus->link_id, id->mfg_id, id->part_id,
+                            id->class_id);
+       } else {
+               /* name shall be sdw:link:mfg:part:class:unique */
+               dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x",
+                            bus->link_id, id->mfg_id, id->part_id,
+                            id->class_id, id->unique_id);
+       }
 
        slave->dev.release = sdw_slave_release;
        slave->dev.bus = &sdw_bus_type;
@@ -103,6 +110,7 @@ static bool find_slave(struct sdw_bus *bus,
 int sdw_acpi_find_slaves(struct sdw_bus *bus)
 {
        struct acpi_device *adev, *parent;
+       struct acpi_device *adev2, *parent2;
 
        parent = ACPI_COMPANION(bus->dev);
        if (!parent) {
@@ -112,10 +120,46 @@ int sdw_acpi_find_slaves(struct sdw_bus *bus)
 
        list_for_each_entry(adev, &parent->children, node) {
                struct sdw_slave_id id;
+               struct sdw_slave_id id2;
+               bool ignore_unique_id = true;
 
                if (!find_slave(bus, adev, &id))
                        continue;
 
+               /* brute-force O(N^2) search for duplicates */
+               parent2 = parent;
+               list_for_each_entry(adev2, &parent2->children, node) {
+
+                       if (adev == adev2)
+                               continue;
+
+                       if (!find_slave(bus, adev2, &id2))
+                               continue;
+
+                       if (id.sdw_version != id2.sdw_version ||
+                           id.mfg_id != id2.mfg_id ||
+                           id.part_id != id2.part_id ||
+                           id.class_id != id2.class_id)
+                               continue;
+
+                       if (id.unique_id != id2.unique_id) {
+                               dev_dbg(bus->dev,
+                                       "Valid unique IDs %x %x for Slave mfg %x part %d\n",
+                                       id.unique_id, id2.unique_id,
+                                       id.mfg_id, id.part_id);
+                               ignore_unique_id = false;
+                       } else {
+                               dev_err(bus->dev,
+                                       "Invalid unique IDs %x %x for Slave mfg %x part %d\n",
+                                       id.unique_id, id2.unique_id,
+                                       id.mfg_id, id.part_id);
+                               return -ENODEV;
+                       }
+               }
+
+               if (ignore_unique_id)
+                       id.unique_id = SDW_IGNORED_UNIQUE_ID;
+
                /*
                 * don't error check for sdw_slave_add as we want to continue
                 * adding Slaves