On Mon, 30 Mar 2009, Wolfram Sang wrote: > On Mon, Mar 30, 2009 at 03:50:28PM +0200, Guennadi Liakhovetski wrote: > > > Ok, I just was informed, that there is a hardware bug on the board I am > > using. So, please ignore my objections. Sorry for the wasted time. > > Well, not completely wasted: We found a bug :) Patch follows, Ben can > you add it? > > Regards, > > Wolfram > > === > > 'disable_delay' was static which is wrong as it is calculated using the > per-device > bus speed. This patch turns 'disable_delay' into a per-device variable. > > Reported-by: Sascha Hauer <[email protected]> > Signed-off-by: Wolfram Sang <[email protected]>
Acked-by: Guennadi Liakhovetski <[email protected]> Thanks Guennadi > --- > drivers/i2c/busses/i2c-imx.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > Index: .kernel/drivers/i2c/busses/i2c-imx.c > =================================================================== > --- .kernel.orig/drivers/i2c/busses/i2c-imx.c > +++ .kernel/drivers/i2c/busses/i2c-imx.c > @@ -86,8 +86,6 @@ > /** Variables > ****************************************************************** > > *******************************************************************************/ > > -static unsigned int disable_delay; /* Dummy delay */ > - > /* > * sorted list of clock divider, register value pairs > * taken from table 26-5, p.26-9, Freescale i.MX > @@ -121,6 +119,7 @@ struct imx_i2c_struct { > int irq; > wait_queue_head_t queue; > unsigned long i2csr; > + unsigned int disable_delay; > }; > > /** Functions for IMX I2C adapter driver > *************************************** > @@ -212,7 +211,7 @@ static void i2c_imx_stop(struct imx_i2c_ > * This delay caused by an i.MXL hardware bug. > * If no (or too short) delay, no "STOP" bit will be generated. > */ > - udelay(disable_delay); > + udelay(i2c_imx->disable_delay); > /* Disable I2C controller */ > writeb(0, i2c_imx->base + IMX_I2C_I2CR); > } > @@ -243,7 +242,7 @@ static void __init i2c_imx_set_clk(struc > * This delay is used in I2C bus disable function > * to fix chip hardware bug. > */ > - disable_delay = (500000U * i2c_clk_div[i][0] > + i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0] > + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2); > > /* dev_dbg() can't be used, because adapter is not yet registered */ > > -- > Pengutronix e.K. | Wolfram Sang | > Industrial Linux Solutions | http://www.pengutronix.de/ | > --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
