Re: [PATCH v5] ACPI: Fix acpi_evaluate_object() return value check

From: Bjorn Helgaas
Date: Thu Jan 23 2014 - 13:21:31 EST


On Wed, Jan 22, 2014 at 8:42 PM, Yijing Wang <wangyijing@xxxxxxxxxx> wrote:
> Since acpi_evaluate_object() returns acpi_status and not plain int,
> ACPI_FAILURE() should be used for checking its return value. Also
> add some detailed debug info when acpi_evaluate_object() failed.
>
> Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx>
> Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
> ---
> v4->v5: Add some detailed debug info for acpi_evaluate_object()
> failure suggested by Bjorn.
> v3->v4: Fix spell error, add Jani Nikula reviewed-by.
> v2->v3: Fix compile error pointed out by Hanjun.
> v1->v2: Add CC to related subsystem MAINTAINERS
> ---
> drivers/gpu/drm/i915/intel_acpi.c | 33 ++++++++++++++++-------
> drivers/gpu/drm/nouveau/core/subdev/mxm/base.c | 13 ++++++---
> drivers/gpu/drm/nouveau/nouveau_acpi.c | 25 +++++++++++-------
> drivers/pci/pci-label.c | 10 +++++--
> 4 files changed, 54 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_acpi.c b/drivers/gpu/drm/i915/intel_acpi.c
> index dfff090..e7b526b 100644
> --- a/drivers/gpu/drm/i915/intel_acpi.c
> +++ b/drivers/gpu/drm/i915/intel_acpi.c
> @@ -31,11 +31,13 @@ static const u8 intel_dsm_guid[] = {
> static int intel_dsm(acpi_handle handle, int func)
> {
> struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
> + struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
> struct acpi_object_list input;
> union acpi_object params[4];
> union acpi_object *obj;
> u32 result;
> - int ret = 0;
> + acpi_status status;
> + int ret;
>
> input.count = 4;
> input.pointer = params;
> @@ -50,10 +52,14 @@ static int intel_dsm(acpi_handle handle, int func)
> params[3].package.count = 0;
> params[3].package.elements = NULL;
>
> - ret = acpi_evaluate_object(handle, "_DSM", &input, &output);
> - if (ret) {
> - DRM_DEBUG_DRIVER("failed to evaluate _DSM: %d\n", ret);
> - return ret;
> + status = acpi_evaluate_object(handle, "_DSM", &input, &output);
> + if (ACPI_FAILURE(status)) {
> + acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
> + DRM_DEBUG_DRIVER(
> + "failed to evaluate _DSM for %s, exit status %u\n",
> + (char *)string.pointer, (unsigned int)status);
> + kfree(string.pointer);
> + return -EINVAL;

I said "too bad there isn't an *easy* way" to include more
information. IMHO this is too ugly and error-prone to use
consistently. And if you are going to add more information, why did
you only do it for some of the calls and not others?

I considered adding a %p extension to print the pathname; I don't know
if that's worthwhile or not. I think it would be ideal if we had a
struct device and could use dev_info(), and then a way to connect the
struct device with an ACPI path, like maybe a dmesg note when we
create the struct device corresponding to an ACPI Device node.

Bjorn

> }
>
> obj = (union acpi_object *)output.pointer;
> @@ -138,10 +144,12 @@ static char *intel_dsm_mux_type(u8 type)
> static void intel_dsm_platform_mux_info(void)
> {
> struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
> + struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
> struct acpi_object_list input;
> union acpi_object params[4];
> union acpi_object *pkg;
> - int i, ret;
> + acpi_status status;
> + int i;
>
> input.count = 4;
> input.pointer = params;
> @@ -156,10 +164,15 @@ static void intel_dsm_platform_mux_info(void)
> params[3].package.count = 0;
> params[3].package.elements = NULL;
>
> - ret = acpi_evaluate_object(intel_dsm_priv.dhandle, "_DSM", &input,
> - &output);
> - if (ret) {
> - DRM_DEBUG_DRIVER("failed to evaluate _DSM: %d\n", ret);
> + acpi_status = acpi_evaluate_object(intel_dsm_priv.dhandle,
> + "_DSM", &input, &output);
> + if (ACPI_FAILURE(status)) {
> + acpi_get_name(intel_dsm_priv.dhandle,
> + ACPI_FULL_PATHNAME, &string);
> + DRM_DEBUG_DRIVER(
> + "failed to evaluate _DSM for %s, exit status %u\n",
> + (char *)string.pointer, (unsigned int)status);
> + kfree(string.pointer);
> goto out;
> }
>
> diff --git a/drivers/gpu/drm/nouveau/core/subdev/mxm/base.c b/drivers/gpu/drm/nouveau/core/subdev/mxm/base.c
> index 1291204..c30ee88 100644
> --- a/drivers/gpu/drm/nouveau/core/subdev/mxm/base.c
> +++ b/drivers/gpu/drm/nouveau/core/subdev/mxm/base.c
> @@ -112,17 +112,22 @@ mxm_shadow_dsm(struct nouveau_mxm *mxm, u8 version)
> };
> struct acpi_object_list list = { ARRAY_SIZE(args), args };
> struct acpi_buffer retn = { ACPI_ALLOCATE_BUFFER, NULL };
> + struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
> union acpi_object *obj;
> acpi_handle handle;
> - int ret;
> + acpi_status status;
>
> handle = ACPI_HANDLE(&device->pdev->dev);
> if (!handle)
> return false;
>
> - ret = acpi_evaluate_object(handle, "_DSM", &list, &retn);
> - if (ret) {
> - nv_debug(mxm, "DSM MXMS failed: %d\n", ret);
> + status = acpi_evaluate_object(handle, "_DSM", &list, &retn);
> + if (ACPI_FAILURE(status)) {
> + acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
> + nv_debug(mxm, "DSM MXMS failed for %s: exit status %u\n",
> + (char *)string.pointer,
> + (unsigned int)status);
> + kfree(string.pointer);
> return false;
> }
>
> diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c
> index ba0183f..53d24a7 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_acpi.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c
> @@ -82,7 +82,8 @@ static int nouveau_optimus_dsm(acpi_handle handle, int func, int arg, uint32_t *
> struct acpi_object_list input;
> union acpi_object params[4];
> union acpi_object *obj;
> - int i, err;
> + acpi_status status;
> + int i;
> char args_buff[4];
>
> input.count = 4;
> @@ -101,10 +102,12 @@ static int nouveau_optimus_dsm(acpi_handle handle, int func, int arg, uint32_t *
> args_buff[i] = (arg >> i * 8) & 0xFF;
> params[3].buffer.pointer = args_buff;
>
> - err = acpi_evaluate_object(handle, "_DSM", &input, &output);
> - if (err) {
> - printk(KERN_INFO "failed to evaluate _DSM: %d\n", err);
> - return err;
> + status = acpi_evaluate_object(handle, "_DSM", &input, &output);
> + if (ACPI_FAILURE(status)) {
> + acpi_handle_info(handle,
> + "failed to evaluate _DSM, exit status %u\n",
> + (unsigned int)status);
> + return -EINVAL;
> }
>
> obj = (union acpi_object *)output.pointer;
> @@ -134,7 +137,7 @@ static int nouveau_dsm(acpi_handle handle, int func, int arg, uint32_t *result)
> struct acpi_object_list input;
> union acpi_object params[4];
> union acpi_object *obj;
> - int err;
> + acpi_status status;
>
> input.count = 4;
> input.pointer = params;
> @@ -148,10 +151,12 @@ static int nouveau_dsm(acpi_handle handle, int func, int arg, uint32_t *result)
> params[3].type = ACPI_TYPE_INTEGER;
> params[3].integer.value = arg;
>
> - err = acpi_evaluate_object(handle, "_DSM", &input, &output);
> - if (err) {
> - printk(KERN_INFO "failed to evaluate _DSM: %d\n", err);
> - return err;
> + status = acpi_evaluate_object(handle, "_DSM", &input, &output);
> + if (ACPI_FAILURE(status)) {
> + acpi_handle_info(handle,
> + "failed to evaluate _DSM, exit status %u\n",
> + (unsigned int)status);
> + return -EINVAL;
> }
>
> obj = (union acpi_object *)output.pointer;
> diff --git a/drivers/pci/pci-label.c b/drivers/pci/pci-label.c
> index d51f45a..0216094 100644
> --- a/drivers/pci/pci-label.c
> +++ b/drivers/pci/pci-label.c
> @@ -213,7 +213,7 @@ dsm_get_label(acpi_handle handle, int func,
> union acpi_object *obj;
> int len = 0;
>
> - int err;
> + acpi_status status;
>
> input.count = 4;
> input.pointer = params;
> @@ -228,9 +228,13 @@ dsm_get_label(acpi_handle handle, int func,
> params[3].package.count = 0;
> params[3].package.elements = NULL;
>
> - err = acpi_evaluate_object(handle, "_DSM", &input, output);
> - if (err)
> + status = acpi_evaluate_object(handle, "_DSM", &input, output);
> + if (ACPI_FAILURE(status)) {
> + acpi_handle_info(handle,
> + "failed to evaluate _DSM, exit status %u\n",
> + (unsigned int)status);
> return -1;
> + }
>
> obj = (union acpi_object *)output->pointer;
>
> --
> 1.7.1
>
>
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