From: Kenji Kaneshige Date: Mon, 10 Nov 2008 04:54:43 +0000 (+0900) Subject: PCI: ignore bit0 of _OSC return code X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2485b8674bf5762822e14e1554938e36511c0ae4;p=linux-beck.git PCI: ignore bit0 of _OSC return code 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 4e39432f4df544d3dfe4fc90a22d87de64d15815 which changed pci_osc_control_set() to use __acpi_query_osc(). Tested-by:"Tomasz Czernecki Signed-off-by: Kenji Kaneshige Signed-off-by: Jesse Barnes --- diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index b3a63edb6901..ae5ec76dca77 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -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");