In message <[EMAIL PROTECTED]> you wrote: > > The TQMA31, as well as the mx32ads use the General Purpose Timer 1, > which is feeded by a 32768 clock (possibly imx31_litekit and > imx31_phycore with 32000 Hz? I don't know.). The prescale divider can > only be an integer. 32768/1000 = non-integer.
I think other architectures hav / had similar issues. See for example the MIPS fixes that were added some time ago. > Currently, I see only one way to solve this: > 1. Patch the common file cpu/arm1136/mx31/interrupts.c, function > interrupt_init(), so that the prescaler divides by 33. > Alternatively, also make the divider a board specific define. > 2. Patch all mx31 board config header files with CFG_HZ 1000. > 3. All mx31 boards have to be tested. Sounds like a plan. > And while we are at the timers: > The udelay function is the next problem: > udelay cannot go below 1/(32768 Hz) = 30.5 micros > The current function inserts a theoretical nop if the requested usec > value is below 1000. Therefore, IMHO, this timer is relatively > imprecise, because the resulting delay is below 1 microsecond. > IMHO, this all because of that slow input clock. How is this handled in Linux? I don't think they would let this go through? Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: [EMAIL PROTECTED] Speed of a tortoise breaking the sound barrier = 1 Machturtle ------------------------------------------------------------------------- Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW! Studies have shown that voting for your favorite open source project, along with a healthy diet, reduces your potential for chronic lameness and boredom. Vote Now at http://www.sourceforge.net/community/cca08 _______________________________________________ U-Boot-Users mailing list U-Boot-Users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/u-boot-users
