On Thursday 23 August 2012 12:12 AM, Felipe Balbi wrote:
>> > if (_dev->flags & OMAP_I2C_FLAG_RESET_REGS_POSTIDLE) {
>> > omap_i2c_write_reg(_dev, OMAP_I2C_CON_REG, 0);
>> > @@ -1266,6 +1267,15 @@ static int omap_i2c_runtime_resume(struct device *dev)
>> > omap_i2c_write_reg(_dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
>> > }
>> >
>> > + while (!(omap_i2c_read_reg(_dev, OMAP_I2C_SYSS_REG) &
>> > + SYSS_RESETDONE_MASK)) {
>> > + if (time_after(jiffies, timeout)) {
>> > + dev_warn(dev, "timeout waiting for controller reset\n");
>> > + return -ETIMEDOUT;
>> > + }
>> > + msleep(1);
>> > + }
>> > +
>> > /*
>> > * Don't write to this register if the IE state is 0 as it can
>> > * cause deadlock.
> That's weird. i2c has SYSS_HAS_RESET_STATUS set, so hwmod framework
> should be checking that for us. And, in fact, SYSS_HAS_RESET_STATUS is
> set on all *data.c files.
Felipe just like writing to sysc reset.
writing
omap_i2c_write_reg(_dev, OMAP_I2C_CON_REG, 0);
[...]
omap_i2c_write_reg(_dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
is also a reset() and the hwmod is not aware of that.
1.Hardware reset: A system bus reset (PIRSTNA = 0).
A device reset causes the system bus reset.
2. Software reset: A software reset by setting the
SRST bit in the I2C_SYSC register. This bit has exactly the same
action on the module logic as the system bus reset.
3. Partial reset or controller reset. The I2C_EN bit in the I2C_CON
register can also reset a part of the I^2 C module. When
the system bus reset is removed (PIRSTNA = 1), I2C_EN = 0 keeps the
functional part of I^2 C module in reset state and all
configuration registers can be accessed.
Since the case 3 is true in my case I am checking and hwmod is not aware
of this.
This read-only bit indicates the state of the reset in case of hardware
reset, global software reset (I2C_SYSC.SRST) or partial software reset
(I2C_CON.I2C_EN).
I am checking for case 3.
>
> When you wrote that patch, did you check that reset hasn't completed
> yet ? I mean, was reset still asserted at that time ? If instead of your
> patch, you just wait longer for reset to complete, will it work ?
>
> diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
> index 6ca8e51..7a39c72 100644
> --- a/arch/arm/mach-omap2/omap_hwmod.c
> +++ b/arch/arm/mach-omap2/omap_hwmod.c
> @@ -156,7 +156,7 @@
> #include "pm.h"
>
> /* Maximum microseconds to wait for OMAP module to softreset */
> -#define MAX_MODULE_SOFTRESET_WAIT 10000
> +#define MAX_MODULE_SOFTRESET_WAIT 50000
>
> /* Name of the OMAP hwmod for the MPU */
> #define MPU_INITIATOR_NAME "mpu"
>
>
> If it does, then reset takes longer to complete on those particular
> boards and it would be nice to know why, but one step at a time :-)
>
> -- balbi
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