[XS] Change in flashrom[main]: reduce DELAY_MINIMUM_SLEEP_US to 100 by default

[Peter Marheine (Code Review)]

Peter Marheine has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/81608?usp=email )

Change subject: reduce DELAY_MINIMUM_SLEEP_US to 100 by default
......................................................................

reduce DELAY_MINIMUM_SLEEP_US to 100 by default

This makes flashrom sleep more eagerly rather than busy-waiting,
observing that most delays in flashrom are either less than 100
microseconds (barely enough time to get any work done, even on a fast
machine) or much more than 1 millisecond (very wasteful to busy-loop).
Since we believe most systems offer good timer resolution that should
provide sleep latency on the order of 100 microseconds, this is a
reasonable default.

For DOS, the default is set to 50ms because the best available timing
source on DOS only ticks at about 20 Hz.

Signed-off-by: Peter Marheine 
Change-Id: I0f431d240c670446218b14811ef62a34e4c83da2
---
M Makefile
M meson_cross/i586_djgpp_dos.txt
M meson_options.txt
3 files changed, 4 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/08/81608/1

diff --git a/Makefile b/Makefile
index 09b31b3..71a7490 100644
--- a/Makefile
+++ b/Makefile
@@ -542,7 +542,7 @@
 # Disable wiki printing by default. It is only useful if you have wiki access.
 CONFIG_PRINT_WIKI ?= no

-CONFIG_DELAY_MINIMUM_SLEEP_US ?= 100000
+CONFIG_DELAY_MINIMUM_SLEEP_US ?= 100

# Disable all features if CONFIG_NOTHING=yes is given unless CONFIG_EVERYTHING was also set
 ifeq ($(CONFIG_NOTHING), yes)
diff --git a/meson_cross/i586_djgpp_dos.txt b/meson_cross/i586_djgpp_dos.txt
index 66d5ed0..4a96e2e 100644
--- a/meson_cross/i586_djgpp_dos.txt
+++ b/meson_cross/i586_djgpp_dos.txt
@@ -25,5 +25,7 @@
 [project options]
 tests = 'disabled'
 ich_descriptors_tool = 'disabled'
+# DOS time resolution is only about 50ms
+delay_minimum_sleep_us = 50000

[properties]
diff --git a/meson_options.txt b/meson_options.txt
index 8a04114..f5e2800 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -22,6 +22,6 @@
 option('documentation', type : 'feature', value : 'auto', description : 'build the html documentation')
 option('ni845x_search_path', type : 'string', value : 'C:\Program Files (x86)\National Instruments\Ni-845x\MS Visual C',
        description : 'Path to search for the proprietary ni845x library and header (32-bit Windows only)')
-option('delay_minimum_sleep_us', type : 'integer', min : 0, value : 100000,
+option('delay_minimum_sleep_us', type : 'integer', min : 0, value : 100,
        description : 'Minimum time in microseconds to suspend execution for (rather than polling) when a delay is required.'
                    + ' Larger values may perform better on machines with low timer resolution, at the cost of increased power.')