Re: Use of mutex in interrupt context flawed/impossible, need advice.

2007-11-22 Thread Robert Hancock
Leon Woestenberg wrote: Hello, I'm converting an out-of-tree (*1) driver from binary semaphore to mutex. Userspace updates a look-up-table using write(). The driver tries to write this LUT to the FPGA in the (video frame) interrupt handler. It is important that the LUT is consistent and thus c

Re: Use of mutex in interrupt context flawed/impossible, need advice.

2007-11-22 Thread Arjan van de Ven
On Thu, 22 Nov 2007 17:02:44 +0100 "Leon Woestenberg" <[EMAIL PROTECTED]> wrote: > Hello, > > > I'm converting an out-of-tree (*1) driver from binary semaphore to > mutex. > > Userspace updates a look-up-table using write(). The driver tries to > write this LUT to the FPGA in the (video frame)

Re: Use of mutex in interrupt context flawed/impossible, need advice.

2007-11-22 Thread Michal Schmidt
On Thu, 22 Nov 2007 17:19:44 +0100 "Leon Woestenberg" <[EMAIL PROTECTED]> wrote: > I forgot to mention that I would like to be prepared for, and use the > -rt patch soon. I understand (maybe wrongly?) that semaphores are not > real-time pre-emptible, mutexes and spinlocks are. Semaphores are pree

Re: Use of mutex in interrupt context flawed/impossible, need advice.

2007-11-22 Thread Leon Woestenberg
Hello, On Nov 22, 2007 5:11 PM, Oliver Neukum <[EMAIL PROTECTED]> wrote: > Am Donnerstag 22 November 2007 schrieb Leon Woestenberg: > > I would like to know why this is not so, and if someone has a cleaner > > proposal than the "try spinlock" approach? > > Keep the semaphore. > I forgot to mention

Re: Use of mutex in interrupt context flawed/impossible, need advice.

2007-11-22 Thread Oliver Neukum
Am Donnerstag 22 November 2007 schrieb Leon Woestenberg: > I would like to know why this is not so, and if someone has a cleaner > proposal than the "try spinlock" approach? Keep the semaphore. Regards Oliver - To unsubscribe from this list: send the line "unsubscribe lin