From 9075e85f46c598e4dfc852b16b256a32e2fb396f Mon Sep 17 00:00:00 2001 From: Peter Lekensteyn Date: Sat, 17 Dec 2011 12:53:43 +0100 Subject: [PATCH] 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 Signed-off-by: Dave Airlie --- drivers/gpu/drm/nouveau/nouveau_acpi.c | 35 +++++++++++++++++++++------------- 1 file changed, 22 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c index 525744d..96756d0 100644 --- a/drivers/gpu/drm/nouveau/nouveau_acpi.c +++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c @@ -18,12 +18,6 @@ #include -#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) -- 2.7.4