[alsa-devel] [bug report] soundwire: Add IO transfer

[Dan Carpenter]

Hello Vinod Koul,

The patch 9d715fa005eb: "soundwire: Add IO transfer" from Dec 14,
2017, leads to the following static checker warning:

	drivers/soundwire/bus.c:309 sdw_nread()
	info: return a literal instead of 'ret'

drivers/soundwire/bus.c
   297  int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
   298  {
   299          struct sdw_msg msg;
   300          int ret;
   301  
   302          ret = sdw_fill_msg(&msg, slave, addr, count,
   303                          slave->dev_num, SDW_MSG_FLAG_READ, val);
   304          if (ret < 0)
   305                  return ret;
   306  
   307          ret = pm_runtime_get_sync(slave->bus->dev);
   308          if (!ret)
   309                  return ret;

Changing "return ret;" to "return 0;" is more readable, but I mostly
am not sure this is correct.  rpm_resume() has crap comments.  It
sometimes returns negatives, sometimes zero and sometimes one but I have
no idea what it means...  Probably this check should be:

		if (ret <= 0)
			return ret;

(Bugs like this is why the static checker warning exists).

   310  
   311          ret = sdw_transfer(slave->bus, &msg);
   312          pm_runtime_put(slave->bus->dev);
   313  
   314          return ret;
   315  }
   316  EXPORT_SYMBOL(sdw_nread);
   317  
   318  /**
   319   * sdw_nwrite() - Write "n" contiguous SDW Slave registers
   320   * @slave: SDW Slave
   321   * @addr: Register address
   322   * @count: length
   323   * @val: Buffer for values to be read
   324   */
   325  int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
   326  {
   327          struct sdw_msg msg;
   328          int ret;
   329  
   330          ret = sdw_fill_msg(&msg, slave, addr, count,
   331                          slave->dev_num, SDW_MSG_FLAG_WRITE, val);
   332          if (ret < 0)
   333                  return ret;
   334  
   335          ret = pm_runtime_get_sync(slave->bus->dev);
   336          if (!ret)
   337                  return ret;

Same static checker warning here.

   338  
   339          ret = sdw_transfer(slave->bus, &msg);
   340          pm_runtime_put(slave->bus->dev);

regards,
dan carpenter