On Thu, Feb 11, 2021 at 07:30:01PM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
>
> Property matching does not work for ACPI fwnodes if the value of the
> given property is not represented as a package in the _DSD package
> containing it. For example, the "compatible" property in the _DSD
> below
>
> Name (_DSD, Package () {
> ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> Package () {
> Package () {"compatible", "ethernet-phy-ieee802.3-c45"}
> }
> })
>
> will not be found by fwnode_property_match_string(), because the ACPI
> code handling device properties does not regard the single value as a
> "list" in that case.
>
> Namely, fwnode_property_match_string() invoked to match a given
> string property value first calls fwnode_property_read_string_array()
> with the last two arguments equal to NULL and 0, respectively, in
> order to count the items in the value of the given property, with the
> assumption that this value may be an array. For ACPI fwnodes, that
> operation is carried out by acpi_node_prop_read() which calls
> acpi_data_prop_read() for this purpose. However, when the return
> (val) pointer is NULL, that function only looks for a property whose
> value is a package without checking the single-value case at all.
>
> To fix that, make acpi_data_prop_read() check the single-value case
> regardless of the return pointer value if its return pointer argument
> is NULL and modify acpi_data_prop_read_single() handling that case to
> attempt to read the value of the property if the return pointer is
> NULL and return 1 if that succeeds.
Thanks, fine with me.
Reviewed-by: Andy Shevchenko <andriy.shevche...@linux.intel.com>
I'll rebase the rest I have on to of this.
> Fixes: 3708184afc77 ("device property: Move FW type specific functionality to
> FW specific files")
> Reported-by: Calvin Johnson <calvin.john...@oss.nxp.com>
> Cc: 4.13+ <sta...@vger.kernel.org> # 4.13+
> Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
> ---
> drivers/acpi/property.c | 44 +++++++++++++++++++++++++++++++++-----------
> 1 file changed, 33 insertions(+), 11 deletions(-)
>
> Index: linux-pm/drivers/acpi/property.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/property.c
> +++ linux-pm/drivers/acpi/property.c
> @@ -787,9 +787,6 @@ static int acpi_data_prop_read_single(co
> const union acpi_object *obj;
> int ret;
>
> - if (!val)
> - return -EINVAL;
> -
> if (proptype >= DEV_PROP_U8 && proptype <= DEV_PROP_U64) {
> ret = acpi_data_get_property(data, propname, ACPI_TYPE_INTEGER,
> &obj);
> if (ret)
> @@ -799,28 +796,43 @@ static int acpi_data_prop_read_single(co
> case DEV_PROP_U8:
> if (obj->integer.value > U8_MAX)
> return -EOVERFLOW;
> - *(u8 *)val = obj->integer.value;
> +
> + if (val)
> + *(u8 *)val = obj->integer.value;
> +
> break;
> case DEV_PROP_U16:
> if (obj->integer.value > U16_MAX)
> return -EOVERFLOW;
> - *(u16 *)val = obj->integer.value;
> +
> + if (val)
> + *(u16 *)val = obj->integer.value;
> +
> break;
> case DEV_PROP_U32:
> if (obj->integer.value > U32_MAX)
> return -EOVERFLOW;
> - *(u32 *)val = obj->integer.value;
> +
> + if (val)
> + *(u32 *)val = obj->integer.value;
> +
> break;
> default:
> - *(u64 *)val = obj->integer.value;
> + if (val)
> + *(u64 *)val = obj->integer.value;
> +
> break;
> }
> +
> + if (!val)
> + return 1;
> } else if (proptype == DEV_PROP_STRING) {
> ret = acpi_data_get_property(data, propname, ACPI_TYPE_STRING,
> &obj);
> if (ret)
> return ret;
>
> - *(char **)val = obj->string.pointer;
> + if (val)
> + *(char **)val = obj->string.pointer;
>
> return 1;
> } else {
> @@ -834,7 +846,7 @@ int acpi_dev_prop_read_single(struct acp
> {
> int ret;
>
> - if (!adev)
> + if (!adev || !val)
> return -EINVAL;
>
> ret = acpi_data_prop_read_single(&adev->data, propname, proptype, val);
> @@ -928,10 +940,20 @@ static int acpi_data_prop_read(const str
> const union acpi_object *items;
> int ret;
>
> - if (val && nval == 1) {
> + if (nval == 1 || !val) {
> ret = acpi_data_prop_read_single(data, propname, proptype, val);
> - if (ret >= 0)
> + /*
> + * The overflow error means that the property is there and it is
> + * single-value, but its type does not match, so return.
> + */
> + if (ret >= 0 || ret == -EOVERFLOW)
> return ret;
> +
> + /*
> + * Reading this property as a single-value one failed, but its
> + * value may still be represented as one-element array, so
> + * continue.
> + */
> }
>
> ret = acpi_data_get_property_array(data, propname, ACPI_TYPE_ANY, &obj);
>
>
>
--
With Best Regards,
Andy Shevchenko
