Re: [PATCH] Look up device file name on device_open

[rekado]

Hi Samuel,

thank you for your comments.

On 09/10/2013 03:03 AM, Samuel Thibault wrote:
> - it should only reopen the master device if master_file is not NULL ;

I assumed that master_file is always non-NULL when master_device is
used, but I was wrong:  I overlooked the call to get_privileged_ports()
that manipulates master_device without depending on master_file.

> - it should close the previous master device before opening another
> one, otherwise you get a port leak on each ds_device_open call.  It

ds_device_close() only returns D_INVALID_OPERATION.  How should the
master device be closed?  Is it enough to deallocate the port?

> then actually becomes useless to call file_name_lookup in parse_opt(),
> and instead call it from ds_device_open itself, and free the port
> there (but only when master_file is not NULL of course). The check for

Well, the call in parse_opt() ensures that devnode fails immediately
when an invalid parameter for device_file is provided.  That's why I
decided to leave it there.  Is it desirable to fail early in this case
or should it only fail when the device is actually accessed in
ds_device_open()?

> master_device == MACH_PORT_NULL in main should of course be turned into
> master_file == NULL.
> 
> Samuel
> 

Rekado