[PATCH 1/2] PRUSS UIO driver support

TK, Pratheesh Gangadhar pratheesh at ti.com
Tue Feb 22 07:06:23 EST 2011


Hi,

> -----Original Message-----
> From: Sergei Shtylyov [mailto:sshtylyov at mvista.com]
> Sent: Tuesday, February 22, 2011 1:23 AM
> To: Hans J. Koch
> Cc: TK, Pratheesh Gangadhar; davinci-linux-open-
> source at linux.davincidsp.com; Arnd Bergmann; Chatterjee, Amit;
> gregkh at suse.de; LKML; Thomas Gleixner; linux-arm-
> kernel at lists.infradead.org
> Subject: Re: [PATCH 1/2] PRUSS UIO driver support
> 
> Hello.
> 
> Hans J. Koch wrote:
> 
> >>> -----Original Message-----
> >>> From: Hans J. Koch [mailto:hjk at hansjkoch.de]
> >>> Sent: Sunday, February 20, 2011 12:04 AM
> >>> To: TK, Pratheesh Gangadhar
> >>> Cc: Thomas Gleixner; Arnd Bergmann; linux-arm-
> kernel at lists.infradead.org;
> >>> davinci-linux-open-source at linux.davincidsp.com; gregkh at suse.de;
> >>> Chatterjee, Amit; Hans J. Koch; LKML
> >>> Subject: Re: [PATCH 1/2] PRUSS UIO driver support
> 
> >>> On Sat, Feb 19, 2011 at 09:10:23PM +0530, TK, Pratheesh Gangadhar
> wrote:
> >>>> For my understanding - if the interrupt is not shared and not level
> triggered -
> >>>> is this okay to have empty handler?
> 
> >>> Greg already said he won't accept that. And I'm quite sure these
> >>> interrupts
> >>> are level triggered, since that is the default on arch/omap.
> 
> >>> E.g. in arch/arm/mach-omap1/irq.c, a loop sets all irqs to level
> triggered
> >>> handling: set_irq_handler(j, handle_level_irq); (line 234)
> 
> >> You should be looking at arch/arm/mach-davinci/irq.c
> 
>     Into arch/arm/mach-davinci/cp_intc.c actually as we're not talking
> about a
> "real" DaVincis here, but about OMAP-L138.
> 
> > Hmpf. I alway get lost in the directory structure of TI SoCs...
> > At least I learned that OMAP3 is in the omap2 directory :)
> 
>     It's probably even more convoluted with DaVinci and friends. :-)
> 
> >> and all interrupts except IRQ_TINT1_TINT34 is set to edge trigger mode
> (line 160).
> 
> > Is that really needed? Level triggered interrupts should certainly be
> > preferred if possible.
> 
>     Don't look there, this code is for "real" DaVincis only.
> 

Thanks for correcting. Interrupts are configured as edge triggered here as well.

Thanks and Regards,
Pratheesh



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