drivers/pc80/tpm: Use stopwatch for timeout-loops

There are manual timeout-loops which use a fixed value and udelay().
In all cases there is a debug printk() inside this loop which, when
enabled, takes way longer than the counted microsecond delay. This
leads to the result that e.g. a 1 second delay takes nearly an eternity
if the debug messages are enabled due to the longer function execution
time.

This patch uses the stopwatch scheme for the timeout-loops which still
makes sure that the timeout period is maintained while it takes longer
function calls like printk() into account. In order to keep the minimum
delay between two register accesses on the TPM keep the udelay(1)-call.

TEST=Enable TPM debug messages on a board where the TPM hits a timeout
by failure and make sure that the debug messages occur in the log
just in the timeout period. It still works as expected if the debug
messages are disabled.

Change-Id: I8fd261c9d60a9a60509c847dbc4983bc05f41d48
Signed-off-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58240
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

0 files changed, 0 insertions, 0 deletions