On Fri, Dec 01, 2017 at 05:36:47PM -0600, Pierre-Louis Bossart wrote:
+/* called with bus_lock held */ +static int sdw_get_device_num(struct sdw_slave *slave) +{
- int bit;
- bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES);
- if (bit == SDW_MAX_DEVICES) {
bit = -ENODEV;goto err;My brain is starting to fry but is this correct? Bit11 seems like a valid value. Should it be bit > 15 (assuming bit 12,13,14 are set to avoid using groups and master)?
this is correct. You are confusing SDW concept and API return types! That should be hint for you to start weekend if you didn't do so :D
This API returns max value it was provided (last arg) if it doesn't find free bit. That's an indication to caller that we ran out of devices hence ENODEV error!
+static int sdw_program_device_num(struct sdw_bus *bus) +{
- u8 buf[SDW_NUM_DEV_ID_REGISTERS] = {0};
- struct sdw_slave *slave, *_s;
- struct sdw_slave_id id;
- struct sdw_msg msg;
- bool found = false;
- int count = 0, ret;
- u64 addr;
- /* No Slave, so use raw xfer api */
- ret = sdw_fill_msg(&msg, NULL, SDW_SCP_DEVID_0,
SDW_NUM_DEV_ID_REGISTERS, 0, SDW_MSG_FLAG_READ, buf);- if (ret < 0)
return ret;- do {
ret = sdw_transfer(bus, NULL, &msg);if (ret == -ENODATA) { /* end of device id reads */ret = 0;break;}if (ret < 0) {dev_err(bus->dev, "DEVID read fail:%d\n", ret);break;}/** Construct the addr and extract. Cast the higher shift* bits to avoid truncation due to size limit.*/addr = buf[5] | (buf[4] << 8) | (buf[3] << 16) |(buf[2] << 24) | ((unsigned long long)buf[1] << 32) |((unsigned long long)buf[0] << 40);sdw_extract_slave_id(bus, addr, &id);/* Now compare with entries */list_for_each_entry_safe(slave, _s, &bus->slaves, node) {if (sdw_compare_devid(slave, id) == 0) {found = true;/** Assign a new dev_num to this Slave and* not mark it present. It will be marked* present after it reports ATTACHED on new* dev_num*/ret = sdw_assign_device_num(slave);if (ret) {dev_err(slave->bus->dev,"Assign dev_num failed:%d",ret);return ret;}break;}}if (found == false) {/* TODO: Park this device in Group 13 */dev_err(bus->dev, "Slave Entry not found");}count++;- } while (ret == 0 && count < (SDW_MAX_DEVICES * 2));
explain that the last condition is intentional - this is not a bug -, some devices can drop off during enumeration and rejoin so might be counted twice.
ok will add