From 106b4a2a78b2a2f14885604891957b84bba502db Mon Sep 17 00:00:00 2001 From: Adrian Betschart Date: Fri, 11 Sep 2026 17:13:14 +0200 Subject: drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validation amdgpu_dm_create_validate_stream_for_sink() walks encoding_order[] and uses the first encoding that validates. YCbCr 4:4:4 is listed before RGB, so an HDMI sink that advertises 4:4:4 gets YCbCr 4:4:4 whenever the "color format" property is left at AUTO, even though RGB fits the same link. That contradicts the documented AUTO behaviour for HDMI in enum drm_connector_color_format (RGB, falling back to YCbCr 4:2:0 only when the bandwidth is not available or the mode is 4:2:0-only), which the amdgpu implementation of the property also describes. It also leaves the "Broadcast RGB" property without effect on such sinks, since the quantization range it selects only applies to RGB output. Try RGB first. The mask still holds every encoding the sink supports, so a mode that cannot carry RGB falls back exactly as before. For reference, v7.2 picked RGB here unless YCbCr 4:4:4 was forced through debugfs, while earlier kernels picked YCbCr 4:4:4 for any HDMI sink that advertised it. Fixes: 0b0ff65d3ca1 ("drm/amd/display: Refactor stream validation") Suggested-by: Adolfo Rodrigues Assisted-by: Claude Code:claude-fable-5-1 Signed-off-by: Adrian Betschart Reviewed-by: Fangzhi Zuo Tested-by: Adolfo Rodrigues Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7) --- drivers/hid/hid-a4tech.c | 167 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 167 insertions(+) create mode 100644 drivers/hid/hid-a4tech.c (limited to 'drivers/hid/hid-a4tech.c') diff --git a/drivers/hid/hid-a4tech.c b/drivers/hid/hid-a4tech.c new file mode 100644 index 000000000..54bfaf611 --- /dev/null +++ b/drivers/hid/hid-a4tech.c @@ -0,0 +1,167 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * HID driver for some a4tech "special" devices + * + * Copyright (c) 1999 Andreas Gal + * Copyright (c) 2000-2005 Vojtech Pavlik + * Copyright (c) 2005 Michael Haboustak for Concept2, Inc + * Copyright (c) 2006-2007 Jiri Kosina + * Copyright (c) 2008 Jiri Slaby + */ + +/* + */ + +#include +#include +#include +#include +#include + +#include "hid-ids.h" + +#define A4_2WHEEL_MOUSE_HACK_7 0x01 +#define A4_2WHEEL_MOUSE_HACK_B8 0x02 + +#define A4_WHEEL_ORIENTATION (HID_UP_GENDESK | 0x000000b8) + +struct a4tech_sc { + unsigned long quirks; + unsigned int hw_wheel; + __s32 delayed_value; +}; + +static int a4_input_mapping(struct hid_device *hdev, struct hid_input *hi, + struct hid_field *field, struct hid_usage *usage, + unsigned long **bit, int *max) +{ + struct a4tech_sc *a4 = hid_get_drvdata(hdev); + + if (a4->quirks & A4_2WHEEL_MOUSE_HACK_B8 && + usage->hid == A4_WHEEL_ORIENTATION) { + /* + * We do not want to have this usage mapped to anything as it's + * nonstandard and doesn't really behave like an HID report. + * It's only selecting the orientation (vertical/horizontal) of + * the previous mouse wheel report. The input_events will be + * generated once both reports are recorded in a4_event(). + */ + return -1; + } + + return 0; + +} + +static int a4_input_mapped(struct hid_device *hdev, struct hid_input *hi, + struct hid_field *field, struct hid_usage *usage, + unsigned long **bit, int *max) +{ + struct a4tech_sc *a4 = hid_get_drvdata(hdev); + + if (usage->type == EV_REL && usage->code == REL_WHEEL_HI_RES) { + set_bit(REL_HWHEEL, *bit); + set_bit(REL_HWHEEL_HI_RES, *bit); + } + + if ((a4->quirks & A4_2WHEEL_MOUSE_HACK_7) && usage->hid == 0x00090007) + return -1; + + return 0; +} + +static int a4_event(struct hid_device *hdev, struct hid_field *field, + struct hid_usage *usage, __s32 value) +{ + struct a4tech_sc *a4 = hid_get_drvdata(hdev); + struct input_dev *input; + + if (!(hdev->claimed & HID_CLAIMED_INPUT) || !field->hidinput) + return 0; + + input = field->hidinput->input; + + if (a4->quirks & A4_2WHEEL_MOUSE_HACK_B8) { + if (usage->type == EV_REL && usage->code == REL_WHEEL_HI_RES) { + a4->delayed_value = value; + return 1; + } + + if (usage->hid == A4_WHEEL_ORIENTATION) { + input_event(input, EV_REL, value ? REL_HWHEEL : + REL_WHEEL, a4->delayed_value); + input_event(input, EV_REL, value ? REL_HWHEEL_HI_RES : + REL_WHEEL_HI_RES, a4->delayed_value * 120); + return 1; + } + } + + if ((a4->quirks & A4_2WHEEL_MOUSE_HACK_7) && usage->hid == 0x00090007) { + a4->hw_wheel = !!value; + return 1; + } + + if (usage->code == REL_WHEEL_HI_RES && a4->hw_wheel) { + input_event(input, usage->type, REL_HWHEEL, value); + input_event(input, usage->type, REL_HWHEEL_HI_RES, value * 120); + return 1; + } + + return 0; +} + +static int a4_probe(struct hid_device *hdev, const struct hid_device_id *id) +{ + struct a4tech_sc *a4; + int ret; + + a4 = devm_kzalloc(&hdev->dev, sizeof(*a4), GFP_KERNEL); + if (a4 == NULL) { + hid_err(hdev, "can't alloc device descriptor\n"); + return -ENOMEM; + } + + a4->quirks = id->driver_data; + + hid_set_drvdata(hdev, a4); + + ret = hid_parse(hdev); + if (ret) { + hid_err(hdev, "parse failed\n"); + return ret; + } + + ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT); + if (ret) { + hid_err(hdev, "hw start failed\n"); + return ret; + } + + return 0; +} + +static const struct hid_device_id a4_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_A4TECH, USB_DEVICE_ID_A4TECH_WCP32PU), + .driver_data = A4_2WHEEL_MOUSE_HACK_7 }, + { HID_USB_DEVICE(USB_VENDOR_ID_A4TECH, USB_DEVICE_ID_A4TECH_X5_005D), + .driver_data = A4_2WHEEL_MOUSE_HACK_B8 }, + { HID_USB_DEVICE(USB_VENDOR_ID_A4TECH, USB_DEVICE_ID_A4TECH_RP_649), + .driver_data = A4_2WHEEL_MOUSE_HACK_B8 }, + { HID_USB_DEVICE(USB_VENDOR_ID_A4TECH, USB_DEVICE_ID_A4TECH_NB_95), + .driver_data = A4_2WHEEL_MOUSE_HACK_B8 }, + { } +}; +MODULE_DEVICE_TABLE(hid, a4_devices); + +static struct hid_driver a4_driver = { + .name = "a4tech", + .id_table = a4_devices, + .input_mapping = a4_input_mapping, + .input_mapped = a4_input_mapped, + .event = a4_event, + .probe = a4_probe, +}; +module_hid_driver(a4_driver); + +MODULE_DESCRIPTION("HID driver for some a4tech \"special\" devices"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1