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author | Len Brown <len.brown@intel.com> | 2010-06-28 20:55:01 -0400 |
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committer | Len Brown <len.brown@intel.com> | 2010-06-28 20:55:01 -0400 |
commit | 3d695839a135a9b3f24b0d7cfd9c4fde2eadd2c5 (patch) | |
tree | 2698b9836ae32ad3f596d68ef65cf81c02a09e4e /drivers/acpi/acpica/evxfevnt.c | |
parent | 93416253073511716f7e70c06e32c3810c3deac4 (diff) | |
download | lwn-3d695839a135a9b3f24b0d7cfd9c4fde2eadd2c5.tar.gz lwn-3d695839a135a9b3f24b0d7cfd9c4fde2eadd2c5.zip |
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>
Diffstat (limited to 'drivers/acpi/acpica/evxfevnt.c')
-rw-r--r-- | 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 d97b8dce1668..18b3f1468b7d 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) |