Hi Daniel, Quick self intro: I have take over drivers/platform/x86 maintainership from Andy; and I'm working my way through the backlog of old patches in patchwork: https://patchwork.kernel.org/project/platform-driver-x86/list/ On 9/2/20 7:38 PM, Daniel Dadap wrote: > Some upcoming notebook designs utilize display muxes driven by a > pair of ACPI methods, MXDM to query and configure the operational > mode of the mux (integrated only, discrete only, hybrid non-muxed, > hybrid with dynamic mux switching), and MXDS to query and set the > mux state when running in dynamic switch mode. > > Add a vga-switcheroo driver to support switching the mux on systems > with the ACPI MXDM/MXDS interface. The mux mode cannot be changed > dynamically (calling MXDM to change the mode won't have effect until > the next boot, and calling MXDM to read the mux mode returns the > active mode, not the mode that will be enabled on next boot), and > MXDS only works when the mux mode is set to dynamic switch, so this > driver will fail to load when MXDM reports any non-dynamic mode. > > This driver currently only supports systems with Intel integrated > graphics and NVIDIA discrete graphics. It will need to be updated if > designs are developed using the same interfaces which utilize GPUs > from other vendors. > > v2,v3: misc. fixes suggested by Barnabás Pőcze <pobrn@xxxxxxxxxxxxxx> > v4: misc. changes suggested by Lukas Wunner <lukas@xxxxxxxxx> According to the discussion archived here: https://patchwork.kernel.org/project/platform-driver-x86/patch/20200902173851.224368-1-ddadap@xxxxxxxxxx/ Andy did a review and you promised a new version, but I don't see a newer version in patchwork. Can you please submit a new version addressing Andy's remarks ? Then I will review and merge the new version. In that discussion you also promised a new version of this patch: https://patchwork.kernel.org/project/platform-driver-x86/patch/20200731202154.11382-1-ddadap@xxxxxxxxxx/ So please also submit a new version of that series. Thanks & Regards, Hans > > Signed-off-by: Daniel Dadap <ddadap@xxxxxxxxxx> > --- > MAINTAINERS | 6 + > drivers/platform/x86/Kconfig | 9 ++ > drivers/platform/x86/Makefile | 2 + > drivers/platform/x86/mxds-gmux.c | 265 +++++++++++++++++++++++++++++++ > 4 files changed, 282 insertions(+) > create mode 100644 drivers/platform/x86/mxds-gmux.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index eeff55560759..636c9259b345 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -11510,6 +11510,12 @@ L: linux-usb@xxxxxxxxxxxxxxx > S: Maintained > F: drivers/usb/musb/ > > +MXDS GMUX DRIVER > +M: Daniel Dadap <ddadap@xxxxxxxxxx> > +L: platform-driver-x86@xxxxxxxxxxxxxxx > +S: Supported > +F: drivers/platform/x86/mxds-gmux.c > + > MXL301RF MEDIA DRIVER > M: Akihiro Tsukada <tskd08@xxxxxxxxx> > L: linux-media@xxxxxxxxxxxxxxx > diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig > index 0ad7ad8cf8e1..5d00ad1ffc0e 100644 > --- a/drivers/platform/x86/Kconfig > +++ b/drivers/platform/x86/Kconfig > @@ -1368,6 +1368,15 @@ config INTEL_TELEMETRY > directly via debugfs files. Various tools may use > this interface for SoC state monitoring. > > +config MXDS_GMUX > + tristate "ACPI MXDS Gmux Driver" > + depends on ACPI_WMI > + depends on ACPI > + depends on VGA_SWITCHEROO > + help > + This driver provides support for ACPI-driven gmux devices which are > + present on some notebook designs with hybrid graphics. > + > endif # X86_PLATFORM_DEVICES > > config PMC_ATOM > diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile > index 53408d965874..b79000733fae 100644 > --- a/drivers/platform/x86/Makefile > +++ b/drivers/platform/x86/Makefile > @@ -146,3 +146,5 @@ obj-$(CONFIG_INTEL_TELEMETRY) += intel_telemetry_core.o \ > intel_telemetry_pltdrv.o \ > intel_telemetry_debugfs.o > obj-$(CONFIG_PMC_ATOM) += pmc_atom.o > + > +obj-$(CONFIG_MXDS_GMUX) += mxds-gmux.o > diff --git a/drivers/platform/x86/mxds-gmux.c b/drivers/platform/x86/mxds-gmux.c > new file mode 100644 > index 000000000000..dd7f6edaf0f3 > --- /dev/null > +++ b/drivers/platform/x86/mxds-gmux.c > @@ -0,0 +1,265 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * mxds-gmux: vga_switcheroo mux handler for ACPI MXDS muxes > + * > + * Copyright (C) 2020 NVIDIA Corporation > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > + * more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program; if not, see <http://www.gnu.org/licenses>. > + * > + */ > + > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > + > +#include <linux/module.h> > +#include <linux/acpi.h> > +#include <linux/pci.h> > +#include <linux/vga_switcheroo.h> > +#include <linux/delay.h> > + > +MODULE_LICENSE("GPL v2"); > +MODULE_DESCRIPTION("vga_switcheroo mux handler for ACPI MXDS muxes"); > +MODULE_AUTHOR("Daniel Dadap <ddadap@xxxxxxxxxx>"); > + > +/* > + * The mux doesn't have its own ACPI HID/CID, or WMI wrapper, so key off of > + * the WMI wrapper for the related WMAA method for backlight control. > + */ > +MODULE_ALIAS("wmi:603E9613-EF25-4338-A3D0-C46177516DB7"); > + > +static struct pci_dev *ig_dev, *dg_dev; > +static acpi_handle internal_mux_handle; > +static acpi_handle external_mux_handle; > + > +enum acpi_method { > + MXDM = 0, > + MXDS, > + NUM_ACPI_METHODS > +}; > + > +static char *acpi_methods[NUM_ACPI_METHODS] = { > + [MXDM] = "MXDM", > + [MXDS] = "MXDS", > +}; > + > +enum mux_mode_command { > + MUX_MODE_GET = 0, > +}; > + > +enum mux_mode { > + MUX_MODE_DGPU_ONLY = 1, > + MUX_MODE_IGPU_ONLY = 2, > + MUX_MODE_MSHYBRID = 3, /* Dual GPU, mux switched to iGPU */ > + MUX_MODE_DYNAMIC = 4, /* Dual GPU, dynamic mux switching */ > +}; > + > +/* > + * Call MXDS with argument value 0 to read the current state. > + * When reading, a return value of 1 means iGPU and 2 means dGPU. > + * Call MXDS with bit 0 set to change the current state. > + * When changing state, clear bit 4 for iGPU and set bit 4 for dGPU. > + */ > + > +enum mux_state { > + MUX_STATE_IGPU = 1, > + MUX_STATE_DGPU = 2, > +}; > + > +enum mux_state_command { > + MUX_STATE_GET = 0, > + MUX_STATE_SET_IGPU = BIT(0), > + MUX_STATE_SET_DGPU = BIT(4) | BIT(0), > +}; > + > +static acpi_integer acpi_helper(acpi_handle handle, enum acpi_method method, > + acpi_integer action) > +{ > + union acpi_object arg = { > + .integer = { .type = ACPI_TYPE_INTEGER, .value = action } > + }; > + struct acpi_object_list in = {.count = 1, .pointer = &arg}; > + acpi_integer ret; > + acpi_status status; > + > + status = acpi_evaluate_integer(handle, acpi_methods[method], &in, &ret); > + > + if (ACPI_FAILURE(status)) { > + pr_err("ACPI %s failed: %s\n", acpi_methods[method], > + acpi_format_exception(status)); > + return 0; > + } > + > + return ret; > +} > + > +static acpi_integer get_mux_mode(acpi_handle handle) > +{ > + return acpi_helper(handle, MXDM, MUX_MODE_GET); > +} > + > +static acpi_integer get_mux_state(acpi_handle handle) > +{ > + return acpi_helper(handle, MXDS, MUX_STATE_GET); > +} > + > +static void set_mux_state(acpi_handle handle, enum mux_state state) > +{ > + enum mux_state_command command; > + > + switch (state) { > + case MUX_STATE_IGPU: > + command = MUX_STATE_SET_IGPU; > + break; > + case MUX_STATE_DGPU: > + command = MUX_STATE_SET_DGPU; > + break; > + default: > + return; > + } > + > + acpi_helper(handle, MXDS, command); > +} > + > +static int mxds_gmux_switchto(enum vga_switcheroo_client_id id) > +{ > + enum mux_state state; > + > + switch (id) { > + case VGA_SWITCHEROO_IGD: > + state = MUX_STATE_IGPU; > + break; > + case VGA_SWITCHEROO_DIS: > + state = MUX_STATE_DGPU; > + break; > + default: > + return -EINVAL; > + } > + > + if (internal_mux_handle) { > + set_mux_state(internal_mux_handle, state); > + if (get_mux_state(internal_mux_handle) != state) > + return -EAGAIN; > + } > + > + if (external_mux_handle) { > + set_mux_state(external_mux_handle, state); > + if (get_mux_state(external_mux_handle) != state) > + return -EAGAIN; > + } > + > + /* DP AUX can take up to 100ms to settle after mux switch */ > + mdelay(100); > + > + return 0; > +} > + > +static enum vga_switcheroo_client_id mxds_gmux_get_client_id( > + struct pci_dev *dev) > +{ > + if (dev == ig_dev) > + return VGA_SWITCHEROO_IGD; > + if (dev == dg_dev) > + return VGA_SWITCHEROO_DIS; > + > + return VGA_SWITCHEROO_UNKNOWN_ID; > +} > + > +static const struct vga_switcheroo_handler handler = { > + .switchto = mxds_gmux_switchto, > + .get_client_id = mxds_gmux_get_client_id, > +}; > + > +static acpi_status find_acpi_methods( > + acpi_handle object, u32 nesting_level, void *context, > + void **return_value) > +{ > + acpi_handle search; > + > + /* If either MXDM or MXDS is missing, we can't use this object */ > + if (acpi_get_handle(object, "MXDM", &search)) > + return AE_OK; > + if (acpi_get_handle(object, "MXDS", &search)) > + return AE_OK; > + > + /* MXDS only works when MXDM indicates dynamic mode */ > + if (get_mux_mode(object) != MUX_MODE_DYNAMIC) > + return AE_OK; > + > + /* Internal display has _BCL; external does not */ > + if (acpi_get_handle(object, "_BCL", &search)) > + external_mux_handle = object; > + else > + internal_mux_handle = object; > + > + return AE_OK; > +} > + > +static int __init mxds_gmux_init(void) > +{ > + int ret = 0; > + struct pci_dev *dev = NULL; > + > + /* Currently only supports Intel integrated and NVIDIA discrete GPUs */ > + while ((dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, dev))) { > + /* Ignore eGPU */ > + if (pci_is_thunderbolt_attached(dev)) > + continue; > + > + switch (dev->vendor) { > + case PCI_VENDOR_ID_INTEL: > + pci_dev_put(ig_dev); > + ig_dev = pci_dev_get(dev); > + break; > + case PCI_VENDOR_ID_NVIDIA: > + pci_dev_put(dg_dev); > + dg_dev = pci_dev_get(dev); > + break; > + default: > + break; > + } > + } > + > + /* Require both integrated and discrete GPUs */ > + if (!ig_dev || !dg_dev) { > + ret = -ENODEV; > + goto done; > + } > + > + acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX, > + find_acpi_methods, NULL, NULL, NULL); > + > + /* Require at least one mux */ > + if (!internal_mux_handle && !external_mux_handle) { > + ret = -ENODEV; > + goto done; > + } > + > + ret = vga_switcheroo_register_handler(&handler, 0); > + > +done: > + > + if (ret) { > + pci_dev_put(ig_dev); > + pci_dev_put(dg_dev); > + } > + > + return ret; > +} > +module_init(mxds_gmux_init); > + > +static void __exit mxds_gmux_exit(void) > +{ > + vga_switcheroo_unregister_handler(); > + pci_dev_put(ig_dev); > + pci_dev_put(dg_dev); > +} > +module_exit(mxds_gmux_exit); 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