use spinlock instead of binary mutex in idt77252 driver

use spinlock instead of binary mutex in idt77252 driver

Quoted 1 line

use spinlock instead of binary mutex in idt77252 driver

I think you really meant: "Use mutex instead of binary semaphore in idt77252 driver", since this is a binary semaphore (not a mutex, which are always binary):

drivers/atm/idt77252.h struct idt77252_dev · line 362

Quoted 1 line

drivers/atm/idt77252.h +0 -1

-	struct semaphore	mutex;

and this is a mutex, not a spinlock:

drivers/atm/idt77252.h struct idt77252_dev · line 362

Quoted 1 line

drivers/atm/idt77252.h +1 -0

+	struct mutex		mutex;

Everything else looks good though

El Sun, Apr 22, 2007 at 07:50:36PM -0400 Kyle Moffett ha dit:

Quoted 6 lines · Matthias Kaehlcke

Quoted 1 line

use spinlock instead of binary mutex in idt77252 driver

I think you really meant: "Use mutex instead of binary semaphore in idt77252 driver", since this is a binary semaphore (not a mutex, which are always binary):

Quoted 6 lines

drivers/atm/idt77252.h struct idt77252_dev · line 362

Quoted 1 line

drivers/atm/idt77252.h +0 -1

-	struct semaphore	mutex;

and this is a mutex, not a spinlock:

drivers/atm/idt77252.h struct idt77252_dev · line 362

Quoted 1 line

drivers/atm/idt77252.h +1 -0

+	struct mutex		mutex;

Everything else looks good though

you're totally right. like in another patch i sent at the same time i messed up the description. as you point out it should read "Use mutex instead of binary semaphore in idt77252 driver". in the last days i reported some spinlock related bugs, i suppose that made me write spinlock instead of mutex ...

thanks for your comments

Signature · 11 lines

Matthias Kaehlcke
Linux Application Developer
Barcelona

                If you don't know where you are going,
               you will probably end up somewhere else
                         (Laurence J. Peter)
                                                                 .''`.
    using free software / Debian GNU/Linux | http://debian.org  : :'  :
                                                                `. `'`
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Please note that the semaphore is used to lock the idt77252 config tables among multiple users including atmsigd even on single processor machines. Does this work with mutexes?

El Mon, Apr 23, 2007 at 09:16:08AM +0200 Eddie C. Dost ha dit:

Quoted 3 lines

Please note that the semaphore is used to lock the idt77252 config tables among multiple users including atmsigd even on single processor machines. Does this work with mutexes?

afaik mutexes have the same behaviour as binary semaphores that are used as mutexes (always locked and unlocked by the same process/thread):

".. the semaphore type can officially be considered to be on its way out. New code should not use semaphores, and old code which uses semaphores as mutexes should be converted over when an opportunity presents itself."

http://lwn.net/Articles/167034/

please correct me if i'm wrong, i'm just doing my first steps with linux kernel development

regards

Signature · 11 lines

Matthias Kaehlcke
Linux Application Developer
Barcelona

    C treats you like a consenting adult. Pascal treats you like a
          naughty child. Ada treats you like a criminal
                      (Bruce Powel Douglass)
                                                                 .''`.
    using free software / Debian GNU/Linux | http://debian.org  : :'  :
                                                                `. `'`
gpg --keyserver pgp.mit.edu --recv-keys 47D8E5D4                  `-

as long as mutexes are not converted to nop when CONFIG_SMP is not defined (I don't know what current kernels do), this is of course correct. You need to verify the headerfiles for the above.

Quoted 19 lines

El Mon, Apr 23, 2007 at 09:16:08AM +0200 Eddie C. Dost ha dit:

Quoted 3 lines

Please note that the semaphore is used to lock the idt77252 config tables among multiple users including atmsigd even on single processor machines. Does this work with mutexes?

afaik mutexes have the same behaviour as binary semaphores that are used as mutexes (always locked and unlocked by the same process/thread):

".. the semaphore type can officially be considered to be on its way out. New code should not use semaphores, and old code which uses semaphores as mutexes should be converted over when an opportunity presents itself."

http://lwn.net/Articles/167034/

please correct me if i'm wrong, i'm just doing my first steps with linux kernel development

as long as mutexes are not converted to nop when CONFIG_SMP is not defined (I don't know what current kernels do), this is of course correct. You need to verify the headerfiles for the above.

Quoted 8 lines

El Mon, Apr 23, 2007 at 09:16:08AM +0200 Eddie C. Dost ha dit:

Quoted 3 lines

Please note that the semaphore is used to lock the idt77252 config tables among multiple users including atmsigd even on single processor machines. Does this work with mutexes?

afaik mutexes have the same behaviour as binary semaphores that are used as mutexes (always locked and unlocked by the same process/thread):

Quoted 1 line · Matthias Kaehlcke

use spinlock instead of binary mutex in idt77252 driver

I think you really meant: "Use mutex instead of binary semaphore in idt77252 driver", since this is a binary semaphore (not a mutex, which are always binary):

Quoted 6 lines · Matthias Kaehlcke

Quoted 1 line

use spinlock instead of binary mutex in idt77252 driver

I think you really meant: "Use mutex instead of binary semaphore in idt77252 driver", since this is a binary semaphore (not a mutex, which are always binary):

And the binary semaphore terminology i a little confusing. struct semaphore is a full counting semaphore that is only used as a binary semaphore if we want to speak in CS terms. Than everyone else just caled them semaphore before these patches started to show up :)

use spinlock instead of binary mutex in idt77252 driver

Signed-off-by Matthias Kaehlcke <[email protected]>

--

drivers/atm/idt77252.c +0 -0

index b4b8014..e3cf141 100644