On Tue, 20 Jan 2009 12:18:24 +0100 Holger Macht <hmacht@xxxxxxx> wrote: > Cc: stable@xxxxxxxxxx The patch applied OK to 2.6.28 but not to any earlier kernel. If we decide that it should be backported to 2.6.27 or earlier, a new patch might be needed for that. > Some devices trigger a DEVICE_CHECK on every evalutation of _STA. This > can also be seen in commit 8b59560a3baf2e7c24e0fb92ea5d09eca92805db > (ACPI: dock: avoid check _STA method). If an undock is processed, the > dock driver sends a uevent and userspace might read the show_docked > property in sysfs. This causes an evaluation of _STA of the particular > device which causes the dock driver to immediately dock again. > > In any case, evaluation of _STA (show_docked) does not necessarily mean > that we are docked, so check with the internal device structure. > > http://bugzilla.kernel.org/show_bug.cgi?id=12360 > > Signed-off-by: Holger Macht <hmacht@xxxxxxx> > --- > > diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c > index 5b30b8d..afd5db3 100644 > --- a/drivers/acpi/dock.c > +++ b/drivers/acpi/dock.c > @@ -855,10 +855,14 @@ fdd_out: > static ssize_t show_docked(struct device *dev, > struct device_attribute *attr, char *buf) > { > + struct acpi_device *tmp; > + > struct dock_station *dock_station = *((struct dock_station **) > dev->platform_data); > - return snprintf(buf, PAGE_SIZE, "%d\n", dock_present(dock_station)); > > + if (ACPI_SUCCESS(acpi_bus_get_device(dock_station->handle, &tmp))) > + return snprintf(buf, PAGE_SIZE, "1\n"); > + return snprintf(buf, PAGE_SIZE, "0\n"); > } > static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL); That seems a little overwrought. Won't plain old strcpy suffice? --- a/drivers/acpi/dock.c~acpi-dock-dont-eval-_sta-on-every-show_docked-sysfs-read-simplification +++ a/drivers/acpi/dock.c @@ -861,8 +861,8 @@ static ssize_t show_docked(struct device dev->platform_data); if (ACPI_SUCCESS(acpi_bus_get_device(dock_station->handle, &tmp))) - return snprintf(buf, PAGE_SIZE, "1\n"); - return snprintf(buf, PAGE_SIZE, "0\n"); + return strcpy(buf, "1\n"); + return strcpy(buf, "0\n"); } static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL); _ -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
