From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- drivers/input/touchscreen/tsc2004.c | 73 +++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 drivers/input/touchscreen/tsc2004.c (limited to 'drivers/input/touchscreen/tsc2004.c') diff --git a/drivers/input/touchscreen/tsc2004.c b/drivers/input/touchscreen/tsc2004.c new file mode 100644 index 000000000..130aeb735 --- /dev/null +++ b/drivers/input/touchscreen/tsc2004.c @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * TSC2004 touchscreen driver + * + * Copyright (C) 2015 QWERTY Embedded Design + * Copyright (C) 2015 EMAC Inc. + */ + +#include +#include +#include +#include +#include +#include "tsc200x-core.h" + +static const struct input_id tsc2004_input_id = { + .bustype = BUS_I2C, + .product = 2004, +}; + +static int tsc2004_cmd(struct device *dev, u8 cmd) +{ + u8 tx = TSC200X_CMD | TSC200X_CMD_12BIT | cmd; + s32 data; + struct i2c_client *i2c = to_i2c_client(dev); + + data = i2c_smbus_write_byte(i2c, tx); + if (data < 0) { + dev_err(dev, "%s: failed, command: %x i2c error: %d\n", + __func__, cmd, data); + return data; + } + + return 0; +} + +static int tsc2004_probe(struct i2c_client *i2c) + +{ + return tsc200x_probe(&i2c->dev, i2c->irq, &tsc2004_input_id, + devm_regmap_init_i2c(i2c, &tsc200x_regmap_config), + tsc2004_cmd); +} + +static const struct i2c_device_id tsc2004_idtable[] = { + { .name = "tsc2004" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, tsc2004_idtable); + +#ifdef CONFIG_OF +static const struct of_device_id tsc2004_of_match[] = { + { .compatible = "ti,tsc2004" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, tsc2004_of_match); +#endif + +static struct i2c_driver tsc2004_driver = { + .driver = { + .name = "tsc2004", + .dev_groups = tsc200x_groups, + .of_match_table = of_match_ptr(tsc2004_of_match), + .pm = pm_sleep_ptr(&tsc200x_pm_ops), + }, + .id_table = tsc2004_idtable, + .probe = tsc2004_probe, +}; +module_i2c_driver(tsc2004_driver); + +MODULE_AUTHOR("Michael Welling "); +MODULE_DESCRIPTION("TSC2004 Touchscreen Driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1