From: Bjorn Helgaas <[email protected]>
9778c14b4ca2 ("ACPI/PCI: Fix possible race condition on _OSC evaluation")
added locking around _OSC calls to protect the acpi_osc_data_list that
stored the results.
63f10f0f6df4 ("PCI/ACPI: move _OSC code to pci_root.c") moved the results
from acpi_osc_data_list to the struct acpi_pci_root, where it no longer
needs locking, but did not remove the lock.
Remove the unnecessary locking around _OSC calls.
Signed-off-by: Bjorn Helgaas <[email protected]>
---
drivers/acpi/pci_root.c | 30 ++++++++++--------------------
1 file changed, 10 insertions(+), 20 deletions(-)
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 51dec352b8b8..a001f8f56b4b 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -56,8 +56,6 @@ static struct acpi_scan_handler pci_root_handler = {
},
};
-static DEFINE_MUTEX(osc_lock);
-
/**
* acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
* @handle: the ACPI CA node in question.
@@ -223,12 +221,7 @@ static acpi_status acpi_pci_query_osc(struct acpi_pci_root
*root,
static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
{
- acpi_status status;
-
- mutex_lock(&osc_lock);
- status = acpi_pci_query_osc(root, flags, NULL);
- mutex_unlock(&osc_lock);
- return status;
+ return acpi_pci_query_osc(root, flags, NULL);
}
struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
@@ -356,7 +349,7 @@ EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32
req)
{
struct acpi_pci_root *root;
- acpi_status status = AE_OK;
+ acpi_status status;
u32 ctrl, capbuf[3];
if (!mask)
@@ -370,18 +363,16 @@ static acpi_status acpi_pci_osc_control_set(acpi_handle
handle, u32 *mask, u32 r
if (!root)
return AE_NOT_EXIST;
- mutex_lock(&osc_lock);
-
*mask = ctrl | root->osc_control_set;
/* No need to evaluate _OSC if the control was already granted. */
if ((root->osc_control_set & ctrl) == ctrl)
- goto out;
+ return AE_OK;
/* Need to check the available controls bits before requesting them. */
while (*mask) {
status = acpi_pci_query_osc(root, root->osc_support_set, mask);
if (ACPI_FAILURE(status))
- goto out;
+ return status;
if (ctrl == *mask)
break;
decode_osc_control(root, "platform does not support",
@@ -392,19 +383,18 @@ static acpi_status acpi_pci_osc_control_set(acpi_handle
handle, u32 *mask, u32 r
if ((ctrl & req) != req) {
decode_osc_control(root, "not requesting control; platform does
not support",
req & ~(ctrl));
- status = AE_SUPPORT;
- goto out;
+ return AE_SUPPORT;
}
capbuf[OSC_QUERY_DWORD] = 0;
capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
capbuf[OSC_CONTROL_DWORD] = ctrl;
status = acpi_pci_run_osc(handle, capbuf, mask);
- if (ACPI_SUCCESS(status))
- root->osc_control_set = *mask;
-out:
- mutex_unlock(&osc_lock);
- return status;
+ if (ACPI_FAILURE(status))
+ return status;
+
+ root->osc_control_set = *mask;
+ return AE_OK;
}
static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
--
2.25.1
