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| author | Henrique de Moraes Holschuh <hmh@hmh.eng.br> | 2007-10-30 17:46:25 -0200 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2007-11-05 13:07:11 -0500 |
| commit | 4273af8d08c823d5898a2b1c2d0f25b4a8b9eaee (patch) | |
| tree | 822101a563cd5fc7b87ea98498ca9e10ae7f8a02 /drivers/misc/thinkpad_acpi.c | |
| parent | fc589a3ce5f38db6239c147da4f9172a25575ecc (diff) | |
| download | lwn-4273af8d08c823d5898a2b1c2d0f25b4a8b9eaee.tar.gz lwn-4273af8d08c823d5898a2b1c2d0f25b4a8b9eaee.zip | |
ACPI: thinkpad-acpi: fix brightness_set error paths
The code calling brightness_set() can't handle EINTR/ERESTARTSYS well, nor
is it checking brightness_set() return status properly.
Fix it.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/misc/thinkpad_acpi.c')
| -rw-r--r-- | drivers/misc/thinkpad_acpi.c | 34 |
1 files changed, 21 insertions, 13 deletions
diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c index 306daa524c03..8c9430775285 100644 --- a/drivers/misc/thinkpad_acpi.c +++ b/drivers/misc/thinkpad_acpi.c @@ -3278,6 +3278,8 @@ static void brightness_exit(void) static int brightness_update_status(struct backlight_device *bd) { + /* it is the backlight class's job (caller) to handle + * EINTR and other errors properly */ return brightness_set( (bd->props.fb_blank == FB_BLANK_UNBLANK && bd->props.power == FB_BLANK_UNBLANK) ? @@ -3318,6 +3320,7 @@ static int brightness_get(struct backlight_device *bd) return level; } +/* May return EINTR which can always be mapped to ERESTARTSYS */ static int brightness_set(int value) { int cmos_cmd, inc, i, res; @@ -3381,29 +3384,34 @@ static int brightness_read(char *p) static int brightness_write(char *buf) { int level; - int new_level; + int rc; char *cmd; int max_level = (tp_features.bright_16levels) ? 15 : 7; - while ((cmd = next_cmd(&buf))) { - if ((level = brightness_get(NULL)) < 0) - return level; + level = brightness_get(NULL); + if (level < 0) + return level; + while ((cmd = next_cmd(&buf))) { if (strlencmp(cmd, "up") == 0) { - new_level = level == (max_level)? - max_level : level + 1; + if (level < max_level) + level++; } else if (strlencmp(cmd, "down") == 0) { - new_level = level == 0? 0 : level - 1; - } else if (sscanf(cmd, "level %d", &new_level) == 1 && - new_level >= 0 && new_level <= max_level) { - /* new_level set */ + if (level > 0) + level--; + } else if (sscanf(cmd, "level %d", &level) == 1 && + level >= 0 && level <= max_level) { + /* new level set */ } else return -EINVAL; - - brightness_set(new_level); } - return 0; + /* + * Now we know what the final level should be, so we try to set it. + * Doing it this way makes the syscall restartable in case of EINTR + */ + rc = brightness_set(level); + return (rc == -EINTR)? ERESTARTSYS : rc; } static struct ibm_struct brightness_driver_data = { |