From 2fc59fe2ecdca56a68728b6091590c07bb3e358d Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Thu, 19 Dec 2013 20:38:14 +0800 Subject: [PATCH] PCI / pci-label: treat PCI label with index 0 as valid label Current pci-label driver detects ACPI label by checking label index returned by ACPI _DSM method, and treats it as valid if label index is positive. According to ACPI Firmware specification 3.1, zero is also an valid label index. So change code to detect availability of ACPI slot label by checking availaiblity of ACPI _DSM function for PCI label. Signed-off-by: Jiang Liu Signed-off-by: Rafael J. Wysocki --- drivers/pci/pci-label.c | 34 ++++++++++++++++++---------------- 1 file changed, 18 insertions(+), 16 deletions(-) diff --git a/drivers/pci/pci-label.c b/drivers/pci/pci-label.c index f12dcd1dc208..0260b14c8d94 100644 --- a/drivers/pci/pci-label.c +++ b/drivers/pci/pci-label.c @@ -187,7 +187,6 @@ static const char device_label_dsm_uuid[] = { }; enum acpi_attr_enum { - ACPI_ATTR_NONE = 0, ACPI_ATTR_LABEL_SHOW, ACPI_ATTR_INDEX_SHOW, }; @@ -222,20 +221,16 @@ dsm_get_label(struct device *dev, char *buf, enum acpi_attr_enum attr) if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 2 && tmp[0].type == ACPI_TYPE_INTEGER && tmp[1].type == ACPI_TYPE_STRING) { - len = tmp[0].integer.value; - if (buf) { - /* - * This second string element is optional even when - * this _DSM is implemented; when not implemented, - * this entry must return a null string. - */ - if (attr == ACPI_ATTR_INDEX_SHOW) - scnprintf(buf, PAGE_SIZE, "%llu\n", - tmp->integer.value); - else if (attr == ACPI_ATTR_LABEL_SHOW) - dsm_label_utf16s_to_utf8s(tmp + 1, buf); - len = strlen(buf) > 0 ? strlen(buf) : -1; - } + /* + * The second string element is optional even when + * this _DSM is implemented; when not implemented, + * this entry must return a null string. + */ + if (attr == ACPI_ATTR_INDEX_SHOW) + scnprintf(buf, PAGE_SIZE, "%llu\n", tmp->integer.value); + else if (attr == ACPI_ATTR_LABEL_SHOW) + dsm_label_utf16s_to_utf8s(tmp + 1, buf); + len = strlen(buf) > 0 ? strlen(buf) : -1; } ACPI_FREE(obj); @@ -246,7 +241,14 @@ dsm_get_label(struct device *dev, char *buf, enum acpi_attr_enum attr) static bool device_has_dsm(struct device *dev) { - return dsm_get_label(dev, NULL, ACPI_ATTR_NONE) > 0; + acpi_handle handle; + + handle = ACPI_HANDLE(dev); + if (!handle) + return false; + + return !!acpi_check_dsm(handle, device_label_dsm_uuid, 0x2, + 1 << DEVICE_LABEL_DSM); } static umode_t -- 2.20.1