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authorHenrique de Moraes Holschuh <hmh@hmh.eng.br>2008-04-26 01:02:20 -0300
committerLen Brown <len.brown@intel.com>2008-04-29 09:47:00 -0400
commit2d5e94d7ca315f859a0eee1366838e8ad34dd7b2 (patch)
tree3bbf8aff5cc01084984b07da060add73d3c0cd4c /drivers/misc
parent8c74adbc692a3cb040cc69d7ca3dfd86d75860a8 (diff)
ACPI: thinkpad-acpi: rate-limit CMOS/EC unsynced error messages
If userspace applications mess with the CMOS NVRAM, or something causes both the ACPI firmware and thinkpad-acpi to try to change the brightness at the same time, it is possible to have the CMOS and EC registers for the current brightness go out of sync. Should that happen, thinkpad-acpi could be really obnoxious when using a brightness_mode of 3 (both EC and CMOS). Instead of complaining a massive number of times, make sure to complain only once until EC and CMOS are back in sync. Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Cc: Joerg Platte <lists@naasa.net> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/thinkpad_acpi.c22
1 files changed, 15 insertions, 7 deletions
diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c
index 601dbe8b407..7dc6b73e8f5 100644
--- a/drivers/misc/thinkpad_acpi.c
+++ b/drivers/misc/thinkpad_acpi.c
@@ -239,6 +239,7 @@ static struct {
static struct {
u16 hotkey_mask_ff:1;
+ u16 bright_cmos_ec_unsync:1;
} tp_warned;
struct thinkpad_id_data {
@@ -4323,13 +4324,20 @@ static int brightness_get(struct backlight_device *bd)
level = lcmos;
}
- if (brightness_mode == 3 && lec != lcmos) {
- printk(TPACPI_ERR
- "CMOS NVRAM (%u) and EC (%u) do not agree "
- "on display brightness level\n",
- (unsigned int) lcmos,
- (unsigned int) lec);
- return -EIO;
+ if (brightness_mode == 3) {
+ if (lec == lcmos)
+ tp_warned.bright_cmos_ec_unsync = 0;
+ else {
+ if (!tp_warned.bright_cmos_ec_unsync) {
+ printk(TPACPI_ERR
+ "CMOS NVRAM (%u) and EC (%u) do not "
+ "agree on display brightness level\n",
+ (unsigned int) lcmos,
+ (unsigned int) lec);
+ tp_warned.bright_cmos_ec_unsync = 1;
+ }
+ return -EIO;
+ }
}
return level;