On Friday, 5 of September 2008, Li, Shaohua wrote: > > >-----Original Message----- > >From: linux-acpi-owner@xxxxxxxxxxxxxxx [mailto:linux-acpi- > >owner@xxxxxxxxxxxxxxx] On Behalf Of Zhao Yakui > >Sent: Friday, September 05, 2008 9:17 AM > >To: Matthew Garrett > >Cc: Rafael J. Wysocki; Zhang, Rui; lenb@xxxxxxxxxx; linux- > >acpi@xxxxxxxxxxxxxxx; andi@xxxxxxxxxxxxxx > >Subject: Re: [PATCH]: ACPI : Set 32bit and 64bit waking vector in FCAS > >table > > > >On Thu, 2008-09-04 at 13:07 +0100, Matthew Garrett wrote: > >> On Thu, Sep 04, 2008 at 11:37:51AM +0200, Rafael J. Wysocki wrote: > >> > > so it seems that the BIOS sets facs->xfirmware_waking_vector during > >> > > POST, but uses facs->firmware_waking_vector to get back during resume. > >> > > >> > So the BIOS is buggy, so let's add a quirk for it. > >> > >> Does the machine resume in Windows? If so, do we have any evidence that > >> Windows has a quirks list to handle this case? If not, then I suspect > >> that Windows sets both and this is what everyone has tested against. > >The laptop can be resumed on windows.(XP & Vista). And we don't know > >whether there exists the quirk list to handler this case on windows. > >Maybe what you said is right. > >In fact it is harmless when both 32bit and 64bit waking vector in FACS > >table are set. When the system is resumed, BIOS will transfer control to > >the predefined waking vector. As we set the same waking vector, either > >of them is OK. > > > >There exists the difference between 32bit and 64bit waking vector unless > >the waking address is above 4GB. But in fact the waking address is below > >1MB on most machines as the waking address needs to be accessed by BIOS. > > > >So in most cases the 32bit and 64bit waking vector are the same value. > >BIOS can transfer control to either of them. > There was discussion about this issue several months ago (intel's ml), looks > people forgot to take action after the discussion. The spec owner said 64bit > vector is used in protected mode. That is if OS sets it, wakeup code is > called in protected mode by BIOS. So the 64-bit vector shouldn't be used. Well, I read this part of the spec (2.0c, 3.0b) more carefully and it matches what you're saying. Moreover, my understanding of it is that we should actually _clear_ the 64-bit vector on systems that support it, because otherwise the BIOS is supposed to use it and call the wake-up code in protected mode. The appended patch is based on this observation. Thanks, Rafael --- From: Rafael J. Wysocki <rjw@xxxxxxx> ACPI suspend: Always use the 32-bit waking vector According to the ACPI specification 2.0c and later, the 64-bit waking vector should be cleared and the 32-bit waking vector should be used, unless we want the wake-up code to be called by the BIOS in Protected Mode. Moreover, some systems (for example HP dv5-1004nr) are known to fail to resume if the 64-bit waking vector is used. Therefore, modify the code to clear the 64-bit waking vector, for FACS version 1 or greater, and set the 32-bit one before suspend. Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx> --- drivers/acpi/hardware/hwsleep.c | 37 +++++++++++-------------------------- 1 file changed, 11 insertions(+), 26 deletions(-) Index: linux-2.6/drivers/acpi/hardware/hwsleep.c =================================================================== --- linux-2.6.orig/drivers/acpi/hardware/hwsleep.c +++ linux-2.6/drivers/acpi/hardware/hwsleep.c @@ -78,19 +78,17 @@ acpi_set_firmware_waking_vector(acpi_phy return_ACPI_STATUS(status); } - /* Set the vector */ + /* + * According to the ACPI specification 2.0c and later, the 64-bit + * waking vector should be cleared and the 32-bit waking vector should + * be used, unless we want the wake-up code to be called by the BIOS in + * Protected Mode. Some systems (for example HP dv5-1004nr) are known + * to fail to resume if the 64-bit vector is used. + */ + if (facs->version >= 1) + facs->xfirmware_waking_vector = 0; - if ((facs->length < 32) || (!(facs->xfirmware_waking_vector))) { - /* - * ACPI 1.0 FACS or short table or optional X_ field is zero - */ - facs->firmware_waking_vector = (u32) physical_address; - } else { - /* - * ACPI 2.0 FACS with valid X_ field - */ - facs->xfirmware_waking_vector = physical_address; - } + facs->firmware_waking_vector = (u32)physical_address; return_ACPI_STATUS(AE_OK); } @@ -134,20 +132,7 @@ acpi_get_firmware_waking_vector(acpi_phy } /* Get the vector */ - - if ((facs->length < 32) || (!(facs->xfirmware_waking_vector))) { - /* - * ACPI 1.0 FACS or short table or optional X_ field is zero - */ - *physical_address = - (acpi_physical_address) facs->firmware_waking_vector; - } else { - /* - * ACPI 2.0 FACS with valid X_ field - */ - *physical_address = - (acpi_physical_address) facs->xfirmware_waking_vector; - } + *physical_address = (acpi_physical_address)facs->firmware_waking_vector; return_ACPI_STATUS(AE_OK); } -- 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
