From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.221.45 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794697735; b=SlQSPB3ZivGmyUfdGNQK2fuP7k5WxPEMoJCdVsz0trq9O2MdI6H4gEMfYG0Q2dXD90UZ mB4awrpGjlzAtCePWVYeu9d03VYpQoi58qydBk0d3986qhltAYT+wrOnUBZC7KMLERjES rk1Q/4L69HJJDpvstSnqFT4EZXVl/2Vl+UuzyDjFUOaez1cVpp/lh8freNyaRx5KE30sB UQ9wvh/F7OFVnucJz7mo69dbI/c+ZJaKunpsNjRtTzs9CeegTHWFqnKF6vQsv6alnDnHb XSiLXHSPy/OAZKQlZLZjiBx2h5mUiZ9cjper7tAtOwglrmREqO0egA7+Cjd87+3U59g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794697735; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: From:To:Cc:Subject:Date:Message-ID:X-Mailer:In-Reply-To:References: MIME-Version:Content-Transfer-Encoding; bh=hh9ybCpP5y8fCdG/ue0SgeIlejwXAiQet93xa73o/ck=; b=GZEYoad96Me6j7o2W+94eTikElYbEOHaPQ34qLTFk+bsxHDFnIgfRTu/KaxOvun3FS2M UqNwu/BOru/kEd6ClKMirhKQFm4Kl/WRrRqkmffIE1ODF+GuZzh//JdVjabD54725DtR2 1ObtaMy3LjjZGGOvjcho4OYqUDE8xSG7E1T3CvNmBga1PrOtXk2jG4kfuCZz0yTsWB1U5 Hp4kLegJqtVcym5EEacao8XujK579Ip+NzHnkOpIQmn3O4LFOWUYGu24abqM1PlonKIIJ wjBgjYHWvR7z2yiAai8pq24KmA2/EYwTw9b5EDaoDO6kO6nQBojuyjYmuL7EVPofQCQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b="jeFJb/c0"; arc=none smtp.remote-ip=209.85.221.45 Received: from mail-wr1-f45.google.com (mail-wr1-f45.google.com [209.85.221.45]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E18D260A6F5E for ; Sat, 14 Nov 2026 23:08:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org E18D260A6F5E Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=jeFJb/c0 Received: by mail-wr1-f45.google.com with SMTP id ffacd0b85a97d-49412eb1474so1030961f8f.3 for ; Sat, 14 Nov 2026 15:08:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20260707; t=1794697733; x=1795302533; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=hh9ybCpP5y8fCdG/ue0SgeIlejwXAiQet93xa73o/ck=; b=jeFJb/c01M9tftwZV+FhKblIVrnpLKLb+K0qW29KG8tNYlpIt2M0ZA/r3nSu2sNB00 MwRBxF+fvkIJobYzGZlbR9zhP1oSohsw9+QLS/qLiDoNr215xRcFwSxqToxY1PgEr75G yYxSxbq6ZprH62dUFNhBIkEqmEUTIkYo0m3OKc18rbjj+64lwlFKnKcFeT/TuI2fIxO8 PRtGSohTG4gGxMjlnn1dqiOCGxe2BYWtY9zeyiN91yQZltWhb0tuB8CrrBgn1XoUZV6A PZzeLPUWEFUUBdoh7wkx6yS4wTgfvAuxvZ7LbaWK0TgMCAYSd3RO1Vkt4JkvyslI6ypC 8d8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1794697733; x=1795302533; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=hh9ybCpP5y8fCdG/ue0SgeIlejwXAiQet93xa73o/ck=; b=tC/b9FmkhXjHcooIau2G9ucWPUN/vWHxxON1WGviafKWMeTBFhpiB5rkoSZrcB/2tf zPRWnbBPh0jBDqFzoEuoSljX3UhcYKQuSpCj9SCF7h9gaJK/CdrtIcOxRuZSSzwRA8Qh AC9EVMeo/Bc+bR6vcYPE4M2ILlhmvXXEmjuYRQTzUh5fvfn4kqLwOKGqCNmOqKNHgsNq 94IqpGdRgS6z6wOCKaR0eGXr93qIbt9AZbS2qD4c0FplYScc+TaaeO1dEC5kVjisWQ+x FpyVKscDQRMEEfUDTKcMG/TbkQId/sRpSONi0tpkQjD6IM3fEJOd3UOnuC6ErlxXmi3J EeFA== X-Forwarded-Encrypted: i=1; AL+hErHuwv1y6fQrdNMeURvBtA4k9oNb2YOGSoqygT6u5qn3Yc891pjsP4UNLwOHqHyuVVPr4fHyjWfBOKNEq6Y=@vger.kernel.org X-Gm-Message-State: APuU4Z8/TF2aC+VQUaO8bP75eG0tOYOfbG9Vh7X/r0wWbL0tSHoalZFZ CIrHy8qXfSC9pIFxnpqrrRGby1H3naRX1fQQ+6k4naVY/EOYl+TskQ+c X-Gm-Gg: AYBFou14TgMcfxZaA3eLHLbaH5rIb0JZ4v0/3HhAd6SLa80gbKuUUr/I6XLgFuJPUh7 ODud3R0XGUIWCpFB7Qid7Kc9r8YCLx+sqzmfQDIbkHZ0FVWRaf8mu27FqYM2M4yYvr5Xr9PRCXx 07jirQhgR/3TQWjl+Hcyek7+N/DKfe31WRx0pq4eQbFu8QLS7iemBYuN4qqdufqz1U8r4EfE2cl AxOVfgp7A2rN+7GVVy/4gSYfxQNcNRl1nLvCTDKZqJADqh4DlKDBJq3Pr//E5f9PGiEZtsUM1uf fN/DOopeMnylJZjFdQGm/lyq2iYt1EqCw8aCK6GaMhp0hEW4l+gQats/xScNac1aEvbhRWi1z0O Y3lObZeiUxoNtveZU1qhAeSAGoaId5m/qJ9zCV7o8DePZNHpgweYkv4iE4wVtr7PlfGkDnO3JPf Go2dCWiUBH5kZVDCs8nwv5CLPvs3bx943hZCvIsGkKoQzLhztjOgnYRpfqJQMU88jZ7CrsGr5Ng qekz6WGkbKcuv53SkUTQujJBWgOShXNhAkvHNOBV3iZcYmtOabI18T7XffmpfcZkD1JJAj7gzLt d7vNdklNZaAry4OpwUInq7v9bTbj X-Received: by 2002:a05:6000:1a8a:b0:48b:f93:3b87 with SMTP id ffacd0b85a97d-49c726da6e1mr15621389f8f.30.1794697733385; Sat, 14 Nov 2026 15:08:53 -0800 (PST) Received: from m2.. ([37.142.149.161]) by smtp.googlemail.com with ESMTPSA id ffacd0b85a97d-49c5d03b10fsm14910018f8f.1.2026.11.14.15.08.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 14 Nov 2026 15:08:53 -0800 (PST) From: Michael Zaidman To: Jiri Kosina , Benjamin Tissoires Cc: Linus Walleij , Bartosz Golaszewski , Greg Kroah-Hartman , Jiri Slaby , Raman Varabets , Germain Hebert , Christina Quast , Rio Liu , Bruno Giacomazzi , linux-input@vger.kernel.org, linux-serial@vger.kernel.org, linux-gpio@vger.kernel.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Michael Zaidman Subject: [PATCH v3 13/16] HID: ft260: i2c: reject an I2C clock outside the supported range Date: Sun, 15 Nov 2026 01:07:57 +0200 Message-ID: <20261114230800.1344401-14-michael.zaidman@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261114230800.1344401-1-michael.zaidman@gmail.com> References: <20261114230800.1344401-1-michael.zaidman@gmail.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The clock sysfs attribute passes any 16-bit value to the chip. The chip accepts it, reports it back in the I2C status report that clock_show reads, and runs the bus at the 100 kHz default. A read of 2048 bytes takes the same 0.298 s after writing 50, 3500 or 65535 as it does after writing 100, while 60 and 3400 give 0.387 s and 0.058 s. Userspace has no way to see that the value was not applied. Refuse a value outside the 60-3400 kHz range named in the datasheet section 4.4.16. ft260_uart_change_speed() checks the baud rate against FT260_UART_CFG_BAUD_MIN and FT260_UART_CFG_BAUD_MAX, but termios has no error return, so it falls back to 9600. A sysfs store can return an error, so the clock store refuses the value. FT260_WORD_ATTR_STORE() takes the parse function as a parameter now, so a word attribute with no range of its own keeps passing kstrtou16. Signed-off-by: Michael Zaidman --- drivers/hid/hid-ft260.c | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index 5564ed62cc48..391128e4bb35 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -69,6 +69,11 @@ MODULE_PARM_DESC(debug, "Toggle FT260 debugging messages"); #define FT260_WR_I2C_DATA_MAX 60 #define FT260_WR_UART_DATA_MAX 60 + +/* I2C bus clock range in kHz, see the FT260 datasheet section 4.4.16 */ +#define FT260_I2C_CLOCK_MIN 60 +#define FT260_I2C_CLOCK_MAX 3400 + #define FT260_GPIOCHIP "ft260_gpio" #define FT260_GPIO_0_5_COUNT 6 #define FT260_GPIO_A_H_COUNT 8 @@ -1592,6 +1597,25 @@ static void ft260_attr_dummy_func(struct hid_device *hdev, u8 req, u16 value) { } +/* + * The chip takes any 16-bit value and reports it back in the I2C status + * report, but runs the bus at the 100 kHz default when the value is + * outside the documented range. The report gives no way to tell the two + * cases apart, so refuse the value here. + */ +static int ft260_i2c_clock_parse(const char *buf, unsigned int base, u16 *clock) +{ + int ret = kstrtou16(buf, base, clock); + + if (ret) + return ret; + + if (*clock < FT260_I2C_CLOCK_MIN || *clock > FT260_I2C_CLOCK_MAX) + return -EINVAL; + + return 0; +} + #define FT260_ATTR_SHOW(name, reptype, id, type, func) \ static ssize_t name##_show(struct device *kdev, \ struct device_attribute *attr, char *buf) \ @@ -1649,9 +1673,9 @@ static void ft260_attr_dummy_func(struct hid_device *hdev, u8 req, u16 value) FT260_ATTR_STORE(name, reptype, FT260_SYSTEM_SETTINGS, req, \ u8, kstrtou8, func, FT260_STORE_NATIVE) -#define FT260_WORD_ATTR_STORE(name, reptype, req, func) \ +#define FT260_WORD_ATTR_STORE(name, reptype, req, strtou, func) \ FT260_ATTR_STORE(name, reptype, FT260_SYSTEM_SETTINGS, req, \ - u16, kstrtou16, func, cpu_to_le16) + u16, strtou, func, cpu_to_le16) FT260_SSTAT_ATTR_SHOW(chip_mode); static DEVICE_ATTR_RO(chip_mode); @@ -1704,7 +1728,8 @@ static DEVICE_ATTR_RW(clock_ctl); FT260_I2CST_ATTR_SHOW(clock); FT260_WORD_ATTR_STORE(clock, ft260_set_i2c_speed_report, - FT260_SET_I2C_CLOCK_SPEED, ft260_attr_dummy_func); + FT260_SET_I2C_CLOCK_SPEED, ft260_i2c_clock_parse, + ft260_attr_dummy_func); static DEVICE_ATTR_RW(clock); static ssize_t i2c_reset_store(struct device *kdev, -- 2.43.0