Hi, On Sat, Mar 21, 2009 at 09:38:48AM -0400, Jon wrote: > From: Sascha Hauer <s.ha...@pengutronix.de> > > The mpc5xxx i2c driver has great delays while waiting for the chip status. > make the delays smaller and the driver faster. > > Signed-off-by: Sascha Hauer <s.ha...@pengutronix.de> > --- > cpu/mpc5xxx/i2c.c | 6 +++--- > 1 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/cpu/mpc5xxx/i2c.c b/cpu/mpc5xxx/i2c.c > index 843af9c..41feb1d 100644 > --- a/cpu/mpc5xxx/i2c.c > +++ b/cpu/mpc5xxx/i2c.c > @@ -38,7 +38,7 @@ DECLARE_GLOBAL_DATA_PTR; > #error CONFIG_SYS_I2C_MODULE is not properly configured > #endif > > -#define I2C_TIMEOUT 100 > +#define I2C_TIMEOUT 10000 > #define I2C_RETRIES 3 > > struct mpc5xxx_i2c_tap { > @@ -94,7 +94,7 @@ static int wait_for_bb(void) > mpc_reg_out(®s->mcr, 0, 0); > mpc_reg_out(®s->mcr, I2C_EN, 0); > #endif > - udelay(1000); > + udelay(1); > status = mpc_reg_in(®s->msr); > } >
The actual condition we wait for takes only a few useconds to become true, but we wait for at least 1ms. As the I2C EEPROM environment routine reads nearly the complete EEPROM several times during startup the speed gain is enormous. I can't recall if it was intentional to reduce the overall timeout with this patch, but I can imagine that the i2c detect function will be faster aswell. > @@ -109,7 +109,7 @@ static int wait_for_pin(int *status) > *status = mpc_reg_in(®s->msr); > > while (timeout-- && !(*status & I2C_IF)) { > - udelay(1000); > + udelay(1); > *status = mpc_reg_in(®s->msr); Same here. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot