Frans Meulenbroeks wrote: Hi Frans,
> I have sent two small patches that improve the performance a little bit. > > Still I am looking at further ways to improve performance. > Currently writing an svf file of 2.4 MB (9432 lines) takes 2 minutes > (on a 1.2 Ghz PowerPC) (read frequency is 12169) > While acceptable it would be nice to speed it up some more. > > Is it possible to access the gpio pins directly instead of through > sysfs, and if so, how could that be done (and what could be achieved)? Well, the logic of the driver is that it could be used on any processors and architecture, because it uses the standard interface provided by sysfs. Your target is powerPC, mine is ARM based, no problem if you used another one. Of course, you could write a kernel module that does more thing in kernel using gpiolib (I mean, you could replace for example gpio_clock with a single system call, an ioctl for your driver). However, you will miss the possibility to run on different architectures and you have dependencies with your kernel. I changed as suggested by Mike my first implementation replacing direct I/O operations (open/close/write) with the stream functions (fopen, etc). Even if I set them as not buffered, I had the impression (really I have not measured, I have only tested if everything works) that there some penalties on performance. Best regards, Stefano -- ===================================================================== DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: [email protected] ===================================================================== ------------------------------------------------------------------------------ This SF.net email is sponsored by Make an app they can't live without Enter the BlackBerry Developer Challenge http://p.sf.net/sfu/RIM-dev2dev _______________________________________________ UrJTAG-development mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/urjtag-development
