PCI: ignore bit0 of _OSC return code (2485b867) · Commits · 戴 / test

Currently acpi_run_osc() checks all the bits in _OSC result code (the first DWORD in the capabilities buffer) to see error condition. But the bit 0, which doesn't indicate any error, must be ignored. The bit 0 is used as the query flag at _OSC invocation time. Some platforms clear it during _OSC evaluation, but the others don't. On latter platforms, current acpi_run_osc() mis-detects error when _OSC is evaluated with query flag set because it doesn't ignore the bit 0. Because of this, the __acpi_query_osc() always fails on such platforms. And this is the cause of the problem that pci_osc_control_set() doesn't work since the commit which changed pci_osc_control_set() to use __acpi_query_osc(). Tested-by:

"Tomasz Czernecki <czernecki@gmail.com> Signed-off-by:

Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by:

Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/pci-acpi.c

+8 −7

Original line number	Diff line number	Diff line
		@@ -63,7 +63,7 @@ static acpi_status acpi_run_osc(acpi_handle handle,
		union acpi_object in_params[4];
		struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
		union acpi_object *out_obj;
		u32 osc_dw0, flags = osc_args->capbuf[OSC_QUERY_TYPE];
		u32 errors, flags = osc_args->capbuf[OSC_QUERY_TYPE];

		/* Setting up input parameters */
		input.count = 4;
		@@ -92,15 +92,16 @@ static acpi_status acpi_run_osc(acpi_handle handle,
		status = AE_TYPE;
		goto out_kfree;
		}
		osc_dw0 = ((u32 )out_obj->buffer.pointer);
		if (osc_dw0) {
		if (osc_dw0 & OSC_REQUEST_ERROR)
		/* Need to ignore the bit0 in result code */
		errors = ((u32 )out_obj->buffer.pointer) & ~(1 << 0);
		if (errors) {
		if (errors & OSC_REQUEST_ERROR)
		printk(KERN_DEBUG "_OSC request fails\n");
		if (osc_dw0 & OSC_INVALID_UUID_ERROR)
		if (errors & OSC_INVALID_UUID_ERROR)
		printk(KERN_DEBUG "_OSC invalid UUID\n");
		if (osc_dw0 & OSC_INVALID_REVISION_ERROR)
		if (errors & OSC_INVALID_REVISION_ERROR)
		printk(KERN_DEBUG "_OSC invalid revision\n");
		if (osc_dw0 & OSC_CAPABILITIES_MASK_ERROR) {
		if (errors & OSC_CAPABILITIES_MASK_ERROR) {
		if (flags & OSC_QUERY_ENABLE)
		goto out_success;
		printk(KERN_DEBUG "_OSC FW not grant req. control\n");

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