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| author | Zhen Gong <zhengong@usc.edu> | 2020-11-08 01:23:19 -0800 |
|---|---|---|
| committer | Hans de Goede <hdegoede@redhat.com> | 2020-11-09 15:16:30 +0100 |
| commit | 97ab4516205eedde0b6565e47175d825b88d6759 (patch) | |
| tree | 4f111e1d32f22b7832a8c1d661e8285eae4b0ce3 | |
| parent | 3be3955315bdf7e4511514a520a76675a23e86e6 (diff) | |
| download | linux-97ab4516205eedde0b6565e47175d825b88d6759.tar.bz2 | |
platform/x86: intel-hid: fix _DSM function index handling
According to the ACPI spec 9.1.1 _DSM (Device Specific Method),
intel_hid_dsm_fn_mask, acquired from function index 0, is "a buffer
containing one bit for each function index". When validitaing fn_index,
it should be compared with corresponding bit.
This buffer is usually longer than a byte. Depending on whether
INTEL_HID_DSM_HEBC_V2_FN exist, it could be either
"Buffer (0x02) { 0xFF, 0x01 }" or "Buffer (0x02) { 0xFF, 0x03 }".
Probably it won't grow larger according to the description. On older
platforms, available functions could be fewer or not supported at all,
i.e., "Buffer (One) { 0x00 }".
Signed-off-by: Zhen Gong <zhengong@usc.edu>
Link: https://lore.kernel.org/r/CAJCLVRCyp0ASdWTx-PxsrDC9zFBPw0U2AtPip+_Hpj2r5gUPwA@mail.gmail.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
| -rw-r--r-- | drivers/platform/x86/intel-hid.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/platform/x86/intel-hid.c b/drivers/platform/x86/intel-hid.c index 86261970bd8f..9a52e56f75da 100644 --- a/drivers/platform/x86/intel-hid.c +++ b/drivers/platform/x86/intel-hid.c @@ -141,7 +141,7 @@ static bool intel_hid_execute_method(acpi_handle handle, method_name = (char *)intel_hid_dsm_fn_to_method[fn_index]; - if (!(intel_hid_dsm_fn_mask & fn_index)) + if (!(intel_hid_dsm_fn_mask & BIT(fn_index))) goto skip_dsm_exec; /* All methods expects a package with one integer element */ @@ -214,7 +214,19 @@ static void intel_hid_init_dsm(acpi_handle handle) obj = acpi_evaluate_dsm_typed(handle, &intel_dsm_guid, 1, 0, NULL, ACPI_TYPE_BUFFER); if (obj) { - intel_hid_dsm_fn_mask = *obj->buffer.pointer; + switch (obj->buffer.length) { + default: + case 2: + intel_hid_dsm_fn_mask = *(u16 *)obj->buffer.pointer; + break; + case 1: + intel_hid_dsm_fn_mask = *obj->buffer.pointer; + break; + case 0: + acpi_handle_warn(handle, "intel_hid_dsm_fn_mask length is zero\n"); + intel_hid_dsm_fn_mask = 0; + break; + } ACPI_FREE(obj); } |