On Thu, Apr 02, 2009 at 03:10:36PM +0200, Thomas Renninger wrote: > Hi, > > I remember a bug (serial device not working) > related to serial and docking on Lenovo. > I wonder whether this could be related to this fix. > > This one also looks worth adding to stable kernel, at least > after 2.6.30 does not show regressions for a while. > > On Monday 30 March 2009 19:31:06 Witold Szczeponik wrote: > > Subject: Enable PNPACPI _PSx Support, v3 > > > > > > (This is an update to the patch presented earlier in > > http://lkml.org/lkml/2008/12/8/284, with new error handling.) > > > > This patch sets the power of PnP ACPI devices to D0 when they > > are activated and to D3 when they are disabled. The latter is > > in correspondence with the ACPI 3.0 specification, whereas the > > former is added in order to be able to power up a device after > > it has been previously disabled (or when booting up a system). > > (As a consequence, the patch makes the PnP ACPI code more ACPI > > compliant.) > > > > Section 6.2.2 of the ACPI Specification (at least versions 1.0b > > and 3.0a) states: "Prior to running this control method [_DIS], > > the OS[PM] will have already put the device in the D3 state." > > Unfortunately, there is no clear statement as to when to put > > a device in the D0 state. :-( Therefore, the patch executes the > > method calls as _PS3/_DIS and _SRS/_PS0. What is clear: "If the > > device is disabled, _SRS enables the device at the specified > > resources." (From the ACPI 3.0a Specification.) > > > > The patch fixes a problem with some IBM ThinkPads (at least the > > 600E and the 600X) where the serial ports have a dedicated > > power source that needs to be brought up before the serial port > > can be used. Without this patch, the serial port is enabled > > but has no power. (In the past, the tpctl utility had to be > > utilized to turn on the power, but support for this feature > > stopped with version 5.9 as it did not support the more recent > > kernel versions.) > > > > The error handlers that handle any errors that can occur during > > the power up/power down phases return the error codes to the > > caller directly. Comments welcome! :-) > > > > No regressions were observed on hardware that does not require > > this patch. > > > > The patch is applied against 2.6.27.x. > > > > > > Signed-off-by: Witold Szczeponik <Witold.Szczeponik@xxxxxxx> > CC: stable@xxxxxxxxxx > ... What specific git commit id in Linus's tree is this? thanks, greg k-h -- 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
