From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- drivers/hid/hid-gembird.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 113 insertions(+) create mode 100644 drivers/hid/hid-gembird.c (limited to 'drivers/hid/hid-gembird.c') diff --git a/drivers/hid/hid-gembird.c b/drivers/hid/hid-gembird.c new file mode 100644 index 000000000..20a8de766 --- /dev/null +++ b/drivers/hid/hid-gembird.c @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * HID driver for Gembird Joypad, "PC Game Controller" + * + * Copyright (c) 2015 Red Hat, Inc + * Copyright (c) 2015 Benjamin Tissoires + */ + +/* + */ + +#include +#include +#include + +#include "hid-ids.h" + +#define GEMBIRD_START_FAULTY_RDESC 8 + +static const __u8 gembird_jpd_faulty_rdesc[] = { + 0x75, 0x08, /* Report Size (8) */ + 0x95, 0x05, /* Report Count (5) */ + 0x15, 0x00, /* Logical Minimum (0) */ + 0x26, 0xff, 0x00, /* Logical Maximum (255) */ + 0x35, 0x00, /* Physical Minimum (0) */ + 0x46, 0xff, 0x00, /* Physical Maximum (255) */ + 0x09, 0x30, /* Usage (X) */ + 0x09, 0x31, /* Usage (Y) */ + 0x09, 0x32, /* Usage (Z) */ + 0x09, 0x32, /* Usage (Z) */ + 0x09, 0x35, /* Usage (Rz) */ + 0x81, 0x02, /* Input (Data,Var,Abs) */ +}; + +/* + * we fix the report descriptor by: + * - marking the first Z axis as constant (so it is ignored by HID) + * - assign the original second Z to Rx + * - assign the original Rz to Ry + */ +static const __u8 gembird_jpd_fixed_rdesc[] = { + 0x75, 0x08, /* Report Size (8) */ + 0x95, 0x02, /* Report Count (2) */ + 0x15, 0x00, /* Logical Minimum (0) */ + 0x26, 0xff, 0x00, /* Logical Maximum (255) */ + 0x35, 0x00, /* Physical Minimum (0) */ + 0x46, 0xff, 0x00, /* Physical Maximum (255) */ + 0x09, 0x30, /* Usage (X) */ + 0x09, 0x31, /* Usage (Y) */ + 0x81, 0x02, /* Input (Data,Var,Abs) */ + 0x95, 0x01, /* Report Count (1) */ + 0x09, 0x32, /* Usage (Z) */ + 0x81, 0x01, /* Input (Cnst,Arr,Abs) */ + 0x95, 0x02, /* Report Count (2) */ + 0x09, 0x33, /* Usage (Rx) */ + 0x09, 0x34, /* Usage (Ry) */ + 0x81, 0x02, /* Input (Data,Var,Abs) */ +}; + +static const __u8 *gembird_report_fixup(struct hid_device *hdev, __u8 *rdesc, + unsigned int *rsize) +{ + __u8 *new_rdesc; + /* delta_size is > 0 */ + size_t delta_size = sizeof(gembird_jpd_fixed_rdesc) - + sizeof(gembird_jpd_faulty_rdesc); + size_t new_size = *rsize + delta_size; + + if (*rsize >= 31 && !memcmp(&rdesc[GEMBIRD_START_FAULTY_RDESC], + gembird_jpd_faulty_rdesc, + sizeof(gembird_jpd_faulty_rdesc))) { + new_rdesc = devm_kzalloc(&hdev->dev, new_size, GFP_KERNEL); + if (new_rdesc == NULL) + return rdesc; + + dev_info(&hdev->dev, + "fixing Gembird JPD-DualForce 2 report descriptor.\n"); + + /* start by copying the end of the rdesc */ + memcpy(new_rdesc + delta_size, rdesc, *rsize); + + /* add the correct beginning */ + memcpy(new_rdesc, rdesc, GEMBIRD_START_FAULTY_RDESC); + + /* replace the faulty part with the fixed one */ + memcpy(new_rdesc + GEMBIRD_START_FAULTY_RDESC, + gembird_jpd_fixed_rdesc, + sizeof(gembird_jpd_fixed_rdesc)); + + *rsize = new_size; + rdesc = new_rdesc; + } + + return rdesc; +} + +static const struct hid_device_id gembird_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_GEMBIRD, + USB_DEVICE_ID_GEMBIRD_JPD_DUALFORCE2) }, + { } +}; +MODULE_DEVICE_TABLE(hid, gembird_devices); + +static struct hid_driver gembird_driver = { + .name = "gembird", + .id_table = gembird_devices, + .report_fixup = gembird_report_fixup, +}; +module_hid_driver(gembird_driver); + +MODULE_AUTHOR("Benjamin Tissoires "); +MODULE_DESCRIPTION("HID Gembird joypad driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1