Messages in this thread Patch in this message | | | Date | Mon, 28 Jun 2010 23:49:46 -0400 (EDT) | From | Len Brown <> | Subject | Re: 2.6.35-rc3 regression: IBM Maia system is unbootable [ACPI related?] |
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From: Len Brown <len.brown@intel.com> Subject: [PATCH] ACPI: handle systems which asynchoronously enable ACPI mode
Folklore suggested that such systems existed in the pre-history of ACPI.
However, we removed the SCI_EN polling loop from acpi_hw_set_mode() in b430acbd7c4b919886fa7fd92eeb7a695f1940d3 because it delayed resume by 3 seconds on boxes that refused to set SCI_EN.
Matthew removed the call to acpi_enable() from the suspend resume path.
James found a modern system that still needs to be polled upon boot.
So here we restore the workaround, except that we put it in acpi_enable() rather than the low level acpi_hw_set_mode().
https://bugzilla.kernel.org/show_bug.cgi?id=16271
Signed-off-by: Len Brown <len.brown@intel.com> ---
James, What does the IBM system see with this patch?
thanks, -Len
drivers/acpi/acpica/evxfevnt.c | 19 +++++++++++-------- 1 files changed, 11 insertions(+), 8 deletions(-)
diff --git a/drivers/acpi/acpica/evxfevnt.c b/drivers/acpi/acpica/evxfevnt.c index d97b8dc..18b3f14 100644 --- a/drivers/acpi/acpica/evxfevnt.c +++ b/drivers/acpi/acpica/evxfevnt.c @@ -70,6 +70,7 @@ acpi_ev_get_gpe_device(struct acpi_gpe_xrupt_info *gpe_xrupt_info, acpi_status acpi_enable(void) { acpi_status status; + int retry; ACPI_FUNCTION_TRACE(acpi_enable); @@ -98,16 +99,18 @@ acpi_status acpi_enable(void) /* Sanity check that transition succeeded */ - if (acpi_hw_get_mode() != ACPI_SYS_MODE_ACPI) { - ACPI_ERROR((AE_INFO, - "Hardware did not enter ACPI mode")); - return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE); + for (retry = 0; retry < 30000; ++retry) { + if (acpi_hw_get_mode() == ACPI_SYS_MODE_ACPI) { + if (retry != 0) + ACPI_WARNING((AE_INFO, + "Platform took > %d00 usec to enter ACPI mode", retry)); + return_ACPI_STATUS(AE_OK); + } + acpi_os_stall(100); /* 100 usec */ } - ACPI_DEBUG_PRINT((ACPI_DB_INIT, - "Transition to ACPI mode successful\n")); - - return_ACPI_STATUS(AE_OK); + ACPI_ERROR((AE_INFO, "Hardware did not enter ACPI mode")); + return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE); } ACPI_EXPORT_SYMBOL(acpi_enable) -- 1.7.2.rc0
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