Do not unconditionally invoke function 0x1B without checking for its availability, it leads to an infinite loop on some firmware.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=104791 Fixes: 5addcf0a5f0fad ("nouveau: add runtime PM support (v0.9)") Signed-off-by: Peter Wu <peter at lekensteyn.nl> --- drivers/gpu/drm/nouveau/nouveau_acpi.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c index 572ac30..ad273ad 100644 --- a/drivers/gpu/drm/nouveau/nouveau_acpi.c +++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c @@ -45,6 +45,7 @@ static struct nouveau_dsm_priv { bool dsm_detected; bool optimus_detected; + bool optimus_flags_detected; acpi_handle dhandle; acpi_handle rom_handle; } nouveau_dsm_priv; @@ -212,7 +213,8 @@ static const struct vga_switcheroo_handler nouveau_dsm_handler = { }; static void nouveau_dsm_pci_probe(struct pci_dev *pdev, acpi_handle *dhandle_out, - bool *has_mux, bool *has_opt) + bool *has_mux, bool *has_opt, + bool *has_opt_flags) { acpi_handle dhandle; bool supports_mux; @@ -236,6 +238,7 @@ static void nouveau_dsm_pci_probe(struct pci_dev *pdev, acpi_handle *dhandle_out *dhandle_out = dhandle; *has_mux = supports_mux; *has_opt = !!optimus_funcs; + *has_opt_flags = optimus_funcs & (1 << NOUVEAU_DSM_OPTIMUS_FLAGS); if (optimus_funcs) { uint32_t result; @@ -256,6 +259,7 @@ static bool nouveau_dsm_detect(void) acpi_handle dhandle = NULL; bool has_mux = false; bool has_optimus = false; + bool has_optimus_flags = false; int vga_count = 0; bool guid_valid; bool ret = false; @@ -270,13 +274,15 @@ static bool nouveau_dsm_detect(void) while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) { vga_count++; - nouveau_dsm_pci_probe(pdev, &dhandle, &has_mux, &has_optimus); + nouveau_dsm_pci_probe(pdev, &dhandle, &has_mux, &has_optimus, + &has_optimus_flags); } while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_3D << 8, pdev)) != NULL) { vga_count++; - nouveau_dsm_pci_probe(pdev, &dhandle, &has_mux, &has_optimus); + nouveau_dsm_pci_probe(pdev, &dhandle, &has_mux, &has_optimus, + &has_optimus_flags); } /* find the optimus DSM or the old v1 DSM */ @@ -287,6 +293,7 @@ static bool nouveau_dsm_detect(void) printk(KERN_INFO "VGA switcheroo: detected Optimus DSM method %s handle\n", acpi_method_name); nouveau_dsm_priv.optimus_detected = true; + nouveau_dsm_priv.optimus_flags_detected = has_optimus_flags; ret = true; } else if (vga_count == 2 && has_mux && guid_valid) { nouveau_dsm_priv.dhandle = dhandle; @@ -320,8 +327,9 @@ void nouveau_switcheroo_optimus_dsm(void) if (!nouveau_dsm_priv.optimus_detected) return; - nouveau_optimus_dsm(nouveau_dsm_priv.dhandle, NOUVEAU_DSM_OPTIMUS_FLAGS, - 0x3, &result); + if (nouveau_dsm_priv.optimus_flags_detected) + nouveau_optimus_dsm(nouveau_dsm_priv.dhandle, NOUVEAU_DSM_OPTIMUS_FLAGS, + 0x3, &result); nouveau_optimus_dsm(nouveau_dsm_priv.dhandle, NOUVEAU_DSM_OPTIMUS_CAPS, NOUVEAU_DSM_OPTIMUS_SET_POWERDOWN, &result); -- 2.9.0
