dell inspiron 4150 acpi suspend problems (apm is ok)

Hello,

I have a dell inspiron 4150 laptop. Previously it suspended (to ram) and resumed well, when I was using apm. Recently I tried on my latest kernel update to finally evolve and start using acpi. Unfortunately when suspending to ram with acpi (using "acpitool -s") the display comes back garbled and cannot be corrected.

I have the most recent bios version A06 (I doubt any more will come out as the laptop is 2 - 3 years old). My distro is debian unstable (relatively recent) and my kernel versions and power management info sections are listed below. I have the same symptoms whether I do this from an xterm within X11 (xorg) or from the console. After I resume, switching between consoles and X11 does not help. About the only way I can "exit" the situation is to press the power button which triggers acpi to nicely shutdown the machine.

Some google searches showed others with similar problems, but they were all 2
- 4 years ago. What could be the problem, and what could I try to correct it?

thanks for any help,
donfede

######################################

###########
#

# working apm configuration
#
# Linux kernel version: 2.6.22.5

# Power management options (ACPI, APM)
#
CONFIG_PM=y
CONFIG_PM_LEGACY=y
CONFIG_PM_DEBUG=y
# CONFIG_DISABLE_CONSOLE_SUSPEND is not set
# CONFIG_PM_TRACE is not set
# CONFIG_PM_SYSFS_DEPRECATED is not set
# CONFIG_SOFTWARE_SUSPEND is not set

#
# ACPI (Advanced Configuration and Power Interface) Support #
# CONFIG_ACPI is not set
CONFIG_APM=y
# CONFIG_APM_IGNORE_USER_SUSPEND is not set CONFIG_APM_DO_ENABLE=y
CONFIG_APM_CPU_IDLE=y
# CONFIG_APM_DISPLAY_BLANK is not set
# CONFIG_APM_ALLOW_INTS is not set
# CONFIG_APM_REAL_MODE_POWER_OFF is not set

###########
#

# unfortunately not working acpi configuration
#
# Linux kernel version: 2.6.23.9

# Power management options (ACPI, APM)
#
CONFIG_PM=y
# CONFIG_PM_LEGACY is not set
# CONFIG_PM_DEBUG is not set
CONFIG_PM_SLEEP=y
CONFIG_SUSPEND_UP_POSSIBLE=y
CONFIG_SUSPEND=y
CONFIG_HIBERNATION_UP_POSSIBLE=y
CONFIG_HIBERNATION=y
CONFIG_PM_STD_PARTITION="/dev/hda1"
CONFIG_ACPI=y
CONFIG_ACPI_SLEEP=y
CONFIG_ACPI_PROCFS=y
CONFIG_ACPI_PROC_EVENT=y
CONFIG_ACPI_AC=y
CONFIG_ACPI_BATTERY=y
CONFIG_ACPI_BUTTON=y
CONFIG_ACPI_VIDEO=m
CONFIG_ACPI_FAN=y
# CONFIG_ACPI_DOCK is not set
CONFIG_ACPI_PROCESSOR=y
CONFIG_ACPI_THERMAL=y
# CONFIG_ACPI_ASUS is not set
# CONFIG_ACPI_TOSHIBA is not set
# CONFIG_ACPI_CUSTOM_DSDT is not set
CONFIG_ACPI_BLACKLIST_YEAR=0
# CONFIG_ACPI_DEBUG is not set
CONFIG_ACPI_EC=y
CONFIG_ACPI_POWER=y
CONFIG_ACPI_SYSTEM=y
CONFIG_X86_PM_TIMER=y
# CONFIG_ACPI_CONTAINER is not set
# CONFIG_ACPI_SBS is not set
# CONFIG_APM is not set