nouveau: properly check for _DSM function support

According to the ACPI spec version 4, section 9.14.1, _DSM functions
must return a value with the first bit enabled if any DSM functions are
supported for the given UUID and revision ID. For a given function index n
to be marked supported, bit n must be enabled.

Signed-off-by: Peter Lekensteyn <lekensteyn@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Peter Lekensteyn 2011-12-17 12:53:43 +01:00 committed by Dave Airlie
parent 3b32a592ea
commit 9075e85f46
1 changed files with 22 additions and 13 deletions

View File

@ -18,12 +18,6 @@
#include <linux/vga_switcheroo.h>
#define NOUVEAU_DSM_SUPPORTED 0x00
#define NOUVEAU_DSM_SUPPORTED_FUNCTIONS 0x00
#define NOUVEAU_DSM_ACTIVE 0x01
#define NOUVEAU_DSM_ACTIVE_QUERY 0x00
#define NOUVEAU_DSM_LED 0x02
#define NOUVEAU_DSM_LED_STATE 0x00
#define NOUVEAU_DSM_LED_OFF 0x10
@ -35,6 +29,7 @@
#define NOUVEAU_DSM_POWER_SPEED 0x01
#define NOUVEAU_DSM_POWER_STAMINA 0x02
#define NOUVEAU_DSM_OPTIMUS_FN 0x1A
static struct nouveau_dsm_priv {
bool dsm_detected;
bool optimus_detected;
@ -148,6 +143,23 @@ static int nouveau_dsm(acpi_handle handle, int func, int arg, uint32_t *result)
return 0;
}
/* Returns 1 if a DSM function is usable and 0 otherwise */
static int nouveau_test_dsm(acpi_handle test_handle,
int (*dsm_func)(acpi_handle, int, int, uint32_t *),
int sfnc)
{
u32 result = 0;
/* Function 0 returns a Buffer containing available functions. The args
* parameter is ignored for function 0, so just put 0 in it */
if (dsm_func(test_handle, 0, 0, &result))
return 0;
/* ACPI Spec v4 9.14.1: if bit 0 is zero, no function is supported. If
* the n-th bit is enabled, function n is supported */
return result & 1 && result & (1 << sfnc);
}
static int nouveau_dsm_switch_mux(acpi_handle handle, int mux_id)
{
mxm_wmi_call_mxmx(mux_id == NOUVEAU_DSM_LED_STAMINA ? MXM_MXDS_ADAPTER_IGD : MXM_MXDS_ADAPTER_0);
@ -212,8 +224,7 @@ static int nouveau_dsm_pci_probe(struct pci_dev *pdev)
{
acpi_handle dhandle, nvidia_handle;
acpi_status status;
int ret, retval = 0;
uint32_t result;
int retval = 0;
dhandle = DEVICE_ACPI_HANDLE(&pdev->dev);
if (!dhandle)
@ -224,13 +235,11 @@ static int nouveau_dsm_pci_probe(struct pci_dev *pdev)
return false;
}
ret = nouveau_dsm(dhandle, NOUVEAU_DSM_SUPPORTED,
NOUVEAU_DSM_SUPPORTED_FUNCTIONS, &result);
if (ret == 0)
if (nouveau_test_dsm(dhandle, nouveau_dsm, NOUVEAU_DSM_POWER))
retval |= NOUVEAU_DSM_HAS_MUX;
ret = nouveau_optimus_dsm(dhandle, 0, 0, &result);
if (ret == 0)
if (nouveau_test_dsm(dhandle, nouveau_optimus_dsm,
NOUVEAU_DSM_OPTIMUS_FN))
retval |= NOUVEAU_DSM_HAS_OPT;
if (retval)