Dear "J. William Campbell", In message <4e208227.6010...@comcast.net> you wrote: > > If the I2C protocol must be available before interrupts are > available, then udelay must be used. In the above examples, there are > some loops in i2c and spi that appear to be waiting a full second. I > assume they are using udelay because the get_timer feature is not yet > available to them. I also assume that the example in common/usb.c uses
No, this is usually not the case. This long delay is the error case, which most probably will never happen. For the normal case, you want a tight spinning loop that introduces as little additional delay as possible. > True, although I expect you will find the statement "on all the other > architectures" to be false. Many other architectures, yes, all, no. > These other architectures just don't have spi or I2C yet, or if they do, > they don't use it "early". Are you aware of another architecture that cannot provide sub-microsecond timer resolution? Which is it? 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: w...@denx.de Make it right before you make it faster. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
