From 41a8457f3f6f829be1f8f8fa7577a46b9b7223ef Mon Sep 17 00:00:00 2001 From: Srinivas Pandruvada Date: Tue, 27 Jul 2021 09:18:24 -0700 Subject: [PATCH] ACPI: DPTF: Fix reading of attributes The current assumption that methods to read PCH FIVR attributes will return integer, is not correct. There is no good way to return integer as negative numbers are also valid. These read methods return a package of integers. The first integer returns status, which is 0 on success and any other value for failure. When the returned status is zero, then the second integer returns the actual value. This change fixes this issue by replacing acpi_evaluate_integer() with acpi_evaluate_object() and use acpi_extract_package() to extract results. Fixes: 2ce6324eadb01 ("ACPI: DPTF: Add PCH FIVR participant driver") Signed-off-by: Srinivas Pandruvada Cc: 5.10+ # 5.10+ Signed-off-by: Rafael J. Wysocki --- drivers/acpi/dptf/dptf_pch_fivr.c | 51 ++++++++++++++++++++++++++----- 1 file changed, 43 insertions(+), 8 deletions(-) diff --git a/drivers/acpi/dptf/dptf_pch_fivr.c b/drivers/acpi/dptf/dptf_pch_fivr.c index 5fca18296bf6..550b9081fcbc 100644 --- a/drivers/acpi/dptf/dptf_pch_fivr.c +++ b/drivers/acpi/dptf/dptf_pch_fivr.c @@ -9,6 +9,42 @@ #include #include +struct pch_fivr_resp { + u64 status; + u64 result; +}; + +static int pch_fivr_read(acpi_handle handle, char *method, struct pch_fivr_resp *fivr_resp) +{ + struct acpi_buffer resp = { sizeof(struct pch_fivr_resp), fivr_resp}; + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + struct acpi_buffer format = { sizeof("NN"), "NN" }; + union acpi_object *obj; + acpi_status status; + int ret = -EFAULT; + + status = acpi_evaluate_object(handle, method, NULL, &buffer); + if (ACPI_FAILURE(status)) + return ret; + + obj = buffer.pointer; + if (!obj || obj->type != ACPI_TYPE_PACKAGE) + goto release_buffer; + + status = acpi_extract_package(obj, &format, &resp); + if (ACPI_FAILURE(status)) + goto release_buffer; + + if (fivr_resp->status) + goto release_buffer; + + ret = 0; + +release_buffer: + kfree(buffer.pointer); + return ret; +} + /* * Presentation of attributes which are defined for INT1045 * They are: @@ -23,15 +59,14 @@ static ssize_t name##_show(struct device *dev,\ char *buf)\ {\ struct acpi_device *acpi_dev = dev_get_drvdata(dev);\ - unsigned long long val;\ - acpi_status status;\ + struct pch_fivr_resp fivr_resp;\ + int status;\ \ - status = acpi_evaluate_integer(acpi_dev->handle, #method,\ - NULL, &val);\ - if (ACPI_SUCCESS(status))\ - return sprintf(buf, "%d\n", (int)val);\ - else\ - return -EINVAL;\ + status = pch_fivr_read(acpi_dev->handle, #method, &fivr_resp);\ + if (status)\ + return status;\ +\ + return sprintf(buf, "%llu\n", fivr_resp.result);\ } #define PCH_FIVR_STORE(name, method) \