David Hawkins wrote:
Hi all,
We recently debugged a problem where a Flash write on
MPC8349E and MPC8349EA processor boards was accidentally
occurring during board initialization.
Under the right conditions, the write appears to put
the flash into a command-mode, rather than read-data
Wolfgang Denk wrote:
Which exact driver are you referring to? If any driver has such a bug,
it should be fixed.
drivers/i2c/fsl_i2c.c
The function is i2c_init(). I recently posted a patch that added this line of
code:
i2c_bus_speed[0] = set_i2c_bus_speed(dev, gd-i2c1_clk, speed);
Hi Wolfgang,
We recently debugged a problem where a Flash write on
MPC8349E and MPC8349EA processor boards was accidentally
occurring during board initialization.
A write to flash should not matter at all.
Thats what I thought, until I saw the logic analyzer
trace show otherwise ...
This
Hi Jerry,
The fix will also not expose the accidental introduction
of flash writes in the future, it'll just stop those
writes from having any effect.
IOW, it simply hides the bug. :-(
Yeah, I didn't like that as a solution either.
It would be nicer to generate an exception if a write
Hi Timur,
I'm working on a patch that blocks i2c_init() from writing to
global variables before relocation has occurred. But if
you're saying that this patch should not be necessary,
then that would be better.
The I2C patch is necessary.
Whatever was written to i2c_bus_speed[0] was never
David Hawkins wrote:
Hi Jerry,
[snip]
Most processors available today have debug registers. If the
processor used on a given target has a debug register set and the
registers can be set to trigger on a write to a range, that would give
you an exception. You would not necessarily have to
In message [EMAIL PROTECTED] you wrote:
Which exact driver are you referring to? If any driver has such a bug,
it should be fixed.
drivers/i2c/fsl_i2c.c
The function is i2c_init(). I recently posted a patch that added this line
of code:
i2c_bus_speed[0] =
David Hawkins wrote:
Whatever was written to i2c_bus_speed[0] was never actually
written, since the write occurs to flash before relocation,
so whatever the intent of the write was, needs to be fixed.
Prior to relocation, the value of i2c_bus_speed[] is irrelevant. All that
matter is that
Hi Jerry,
One really good trick is how to hook a logic analyzer to those
itty-bitty balls on the processor. Back when I was a boy, processors
had 40 legs and no balls. :-D You must have a board with a logic
analyzer connector.
Thankfully the Freescale MDS boards do have logic
analyzer
In message [EMAIL PROTECTED] you wrote:
We recently debugged a problem where a Flash write on
MPC8349E and MPC8349EA processor boards was accidentally
occurring during board initialization.
A write to flash should not matter at all.
Under the right conditions, the write appears to put
the
Hi all,
We recently debugged a problem where a Flash write on
MPC8349E and MPC8349EA processor boards was accidentally
occurring during board initialization.
Under the right conditions, the write appears to put
the flash into a command-mode, rather than read-data mode,
and further reads from the
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