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| author | Bjorn Helgaas <bhelgaas@google.com> | 2020-06-02 17:27:33 -0500 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2021-01-27 09:38:32 -0600 |
| commit | 866e61fc40c96e7adba62c9e149e96912b10663c (patch) | |
| tree | a2289f204f6a4d88ebf6929715126ad76481351c /drivers/acpi | |
| parent | 1423de718e6a0ce00372ab119fa40060ff50883e (diff) | |
| download | linux-stable-866e61fc40c96e7adba62c9e149e96912b10663c.tar.gz linux-stable-866e61fc40c96e7adba62c9e149e96912b10663c.tar.bz2 linux-stable-866e61fc40c96e7adba62c9e149e96912b10663c.zip | |
PCI/ACPI: Remove unnecessary osc_lock
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 <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/pci_root.c | 30 |
1 files changed, 10 insertions, 20 deletions
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 7d5a4bd4207c..ea08b3298e73 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, |