On Thu, Oct 19, 2017 at 10:54:50AM +0200, Takashi Iwai wrote:
> On Thu, 19 Oct 2017 05:03:19 +0200,
> Vinod Koul wrote:
> > +int sdw_add_bus_master(struct sdw_bus *bus)
> > +{
> > + int ret;
> > +
> > + if (!bus->dev) {
> > + pr_err("SoundWire bus has no device");
> > + return -ENODEV;
> > + }
> > +
> > + mutex_init(&bus->bus_lock);
> > + INIT_LIST_HEAD(&bus->slaves);
> > +
> > + /*
> > + * SDW is an enumerable bus, but devices can be powered off. So,
> > + * they won't be able to report as present.
> > + *
> > + * Create Slave devices based on Slaves described in
> > + * the respective firmware (ACPI/DT)
> > + */
> > +
> > + if (IS_ENABLED(CONFIG_ACPI) && bus->dev && ACPI_HANDLE(bus->dev))
> > + ret = sdw_acpi_find_slaves(bus);
> > + else if (IS_ENABLED(CONFIG_OF) && bus->dev && bus->dev->of_node)
>
> The bus->dev NULL check is already done at the beginning of the
> function, so here are superfluous.
right
> > +static int sdw_delete_slave(struct device *dev, void *data)
> > +{
> > + struct sdw_slave *slave = dev_to_sdw_dev(dev);
> > + struct sdw_bus *bus = slave->bus;
> > +
> > + mutex_lock(&bus->bus_lock);
> > + if (!list_empty(&bus->slaves))
> > + list_del(&slave->node);
>
> You can perform list_del_init() without empty check.
Better :)
>
> > +void sdw_extract_slave_id(struct sdw_bus *bus,
> > + unsigned long long addr, struct sdw_slave_id *id)
>
> Use u64 instead.
okay
> > +{
> > + dev_dbg(bus->dev, "SDW Slave Addr: %llx", addr);
> > +
> > + /*
> > + * Spec definition
> > + * Register Bit Contents
> > + * DevId_0 [7:4] 47:44 sdw_version
> > + * DevId_0 [3:0] 43:40 unique_id
> > + * DevId_1 39:32 mfg_id [15:8]
> > + * DevId_2 31:24 mfg_id [7:0]
> > + * DevId_3 23:16 part_id [15:8]
> > + * DevId_4 15:08 part_id [7:0]
> > + * DevId_5 07:00 class_id
> > + */
> > + id->sdw_version = (addr >> 44) & GENMASK(3, 0);
> > + id->unique_id = (addr >> 40) & GENMASK(3, 0);
> > + id->mfg_id = (addr >> 24) & GENMASK(15, 0);
> > + id->part_id = (addr >> 8) & GENMASK(15, 0);
> > + id->class_id = addr & GENMASK(7, 0);
> > +
> > + dev_info(bus->dev,
> > + "SDW Slave class_id %x, part_id %x, mfg_id %x, unique_id %x,
> > version %x",
> > + id->class_id, id->part_id, id->mfg_id,
> > + id->unique_id, id->sdw_version);
> > +
>
> Do we want to print a message always at each invocation?
Not really, lets make it debug
> > +static int sdw_slave_add(struct sdw_bus *bus,
> > + struct sdw_slave_id *id, struct fwnode_handle *fwnode)
> > +{
> > + struct sdw_slave *slave;
> > + char name[32];
> > + int ret;
> > +
> > + slave = kzalloc(sizeof(*slave), GFP_KERNEL);
> > + if (!slave)
> > + return -ENOMEM;
> > +
> > + /* Initialize data structure */
> > + memcpy(&slave->id, id, sizeof(*id));
> > +
> > + /* name shall be sdw:link:mfg:part:class:unique */
> > + snprintf(name, sizeof(name), "sdw:%x:%x:%x:%x:%x",
> > + bus->link_id, id->mfg_id, id->part_id,
> > + id->class_id, id->unique_id);
>
> You can set the name directly via dev_set_name(). It's printf format,
> after all.
right, am using it but with this string :D
> > + slave->dev.parent = bus->dev;
> > + slave->dev.fwnode = fwnode;
> > + dev_set_name(&slave->dev, "%s", name);
> > + slave->dev.release = sdw_slave_release;
> > + slave->dev.bus = &sdw_bus_type;
> > + slave->bus = bus;
> > + slave->status = SDW_SLAVE_UNATTACHED;
> > + slave->dev_num = 0;
> > +
> > + mutex_lock(&bus->bus_lock);
> > + list_add_tail(&slave->node, &bus->slaves);
> > + mutex_unlock(&bus->bus_lock);
> > +
> > + ret = device_register(&slave->dev);
> > + if (ret) {
> > + dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);
> > +
> > + /*
> > + * On err, don't free but drop ref as this will be freed
> > + * when release method is invoked.
> > + */
> > + put_device(&slave->dev);
>
> Wouldn't it leave a stale link to bus?
yes that needs to be removed too, thanks for pointing
--
~Vinod
