From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794514497; b=LnrBGKzqOVQHXoBtFM8EfltzhHE0C+a0+Jn6QUbB7w3C1BpmTMjoAaPWu0ScPAoxOGrl 8TaZcQ0JSOLxqmbjNgTY+NPCtMTgfV8PqQKD40jJYSqLsjhBHLZRsHUNeKa7xq04tYZsq qBf+AQK77HEYOrukQ+NTW2LyYTSdHFGVa0V75KyAsCQ1cToe3I+oTi6SdnhErEoamoJKp PwysIkT4gq62/Pe+mtEwbeKCIttxsEppTG/iIrZqRS2xXISwG8VQEXvEzLC64yd5nMxF1 IqWfYy5AYTB5FYOSK/zhRYLTQamC6n0szPs+u2D8X4AGNzJz/F+hl/MnDLSIRubvj8w== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794514497; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=g/CZDCoSG3PJAggCcQOSUNIaMatEG4InxHYvQELPhME=; b=Ew6UFfZ26YLnBCKJQ5oxE7s5HqUqnEuixEnJXAmFiLsr/G2FVy59pTewuIcL8/ap57GO wKY+T5BkEgxQkKYQ/LQ9aDvql0Y+kNAg9LfbK+NLVh5x7zUevIZSH2OtdXVRDi3jgUuXP 0HM5E9KzKrzvit7ELctMHw/7W4jgNH+mH2lgO23eHvDR/0BJDkxe1DWDVrcLw3phiCLHK 00B5AEtE4Y/QoHQI2wv2PkesGj9UMAJo59YKG4jTgwWb3VdxQT9a72cE6Bwr0AguoVQR9 x/ZbZGYm8NaI94RDDnVZ6+HXYgFioY9ccYq5mGlQIa8Dq3UtPgGWiPRATufKy5IpxBQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=N+cmq6bT; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9DDB4606A321 for ; Thu, 12 Nov 2026 20:14:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=N+cmq6bT Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0788D1F000C6; Thu, 12 Nov 2026 20:14:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794514497; bh=g/CZDCoSG3PJAggCcQOSUNIaMatEG4InxHYvQELPhME=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=N+cmq6bT8YW43BTcFxT24jExfBmrGUjcXnBAO1bAUH9LU5HREyB1dHCYabZXNkO7P oSCqjWQHgXGDNtiIM2POMhjZcqMDA9kWpSQC3LFmd6p/pOBq8L6KNRy2J2rz+LsPTQ uk3EYzLamEKwpt994p7VPEoVrfwRN2hkfSnSDXTIlAnVQ+OukpHDT5slQFNRR7YXkb XQttU+GoxElFrExRrbbRWti/DerHd9295aiN5gnZMbu8LLFlV0a3THf8nLxeu6mybk JtEbWmGNjpisBEnZ5Qf0HCiz7k14em09WxZMYaHXTdTZMzgYOd6LU0z7Qo5Xt/8Ue5 CgsrIl4NrwNtQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Guenter Roeck , Sashiko , Sasha Levin Subject: [PATCH 6.18.y 2/2] hwmon: (tmp108) Fix initial conversion delay and wait until ready Date: Thu, 12 Nov 2026 15:14:54 -0500 Message-ID: <20261112200225.3377761-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261112200225.3377761-1-sashal@kernel.org> References: <20261109200336-failed-6.18-7cd60538073e@kernel.org> <20261112200225.3377761-1-sashal@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Guenter Roeck [ Upstream commit 7cd60538073e465310c94b2a2f0ea8d2f03768ef ] In tmp108_common_probe(), the driver only adds the 30 ms conversion delay (TMP108_CONVERSION_TIME_MS) to ready_time if the sensor was previously in TMP108_MODE_SHUTDOWN. However, the TMP108 hardware defaults to continuous conversion mode (TMP108_MODE_CONTINUOUS) upon power-on reset, including immediately after enabling the vcc supply regulator during probe, while the temperature register retains its power-on reset value of 0x0000 (0°C) until the first conversion completes. Because the initial mode is not shutdown, the delay is bypassed and early reads via thermal zone registration or sysfs before the first conversion finishes return an uninitialized 0°C reading. In addition, returning -EAGAIN from tmp108_read() while waiting for a conversion to complete after probe or resume can trigger an unnecessary tight retry loop in callers or fail initial reads. Unconditionally set ready_time to TMP108_CONVERSION_TIME_MS ahead in tmp108_common_probe(), track ready_time as ktime_t, and wait for the remaining conversion time in tmp108_read() using usleep_range() instead of returning -EAGAIN. Reported-by: Sashiko Fixes: 66e1c9171339 ("hwmon: Add Texas Instruments TMP108 temperature sensor driver.") Cc: stable@vger.kernel.org Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin --- drivers/hwmon/tmp108.c | 26 +++++++++++--------------- 1 file changed, 11 insertions(+), 15 deletions(-) diff --git a/drivers/hwmon/tmp108.c b/drivers/hwmon/tmp108.c index f8b2d88d14665..cb52b99eda4ab 100644 --- a/drivers/hwmon/tmp108.c +++ b/drivers/hwmon/tmp108.c @@ -14,7 +14,7 @@ #include #include #include -#include +#include #include #include #include @@ -74,7 +74,7 @@ struct tmp108 { struct regmap *regmap; u16 orig_config; - u64 ready_time; + ktime_t ready_time; const struct tmp108_params *params; }; @@ -96,6 +96,7 @@ static int tmp108_read(struct device *dev, enum hwmon_sensor_types type, struct tmp108 *tmp108 = dev_get_drvdata(dev); unsigned int regval; int err, hyst; + s64 delay; if (type == hwmon_chip) { if (attr == hwmon_chip_update_interval) { @@ -125,12 +126,10 @@ static int tmp108_read(struct device *dev, enum hwmon_sensor_types type, switch (attr) { case hwmon_temp_input: - /* Is it too early to return a conversion ? */ - if (time_before64(get_jiffies_64(), tmp108->ready_time)) { - dev_dbg(dev, "%s: Conversion not ready yet..\n", - __func__); - return -EAGAIN; - } + /* Wait if it is too early to return a conversion */ + delay = ktime_us_delta(tmp108->ready_time, ktime_get()); + if (delay > 0) + usleep_range(delay, delay + 1000); err = regmap_read(tmp108->regmap, TMP108_REG_TEMP, ®val); if (err < 0) return err; @@ -363,11 +362,8 @@ static int tmp108_common_probe(struct device *dev, struct regmap *regmap, char * return err; } - tmp108->ready_time = get_jiffies_64(); - if ((tmp108->orig_config & TMP108_CONF_MODE_MASK) == - TMP108_MODE_SHUTDOWN) - tmp108->ready_time += - msecs_to_jiffies(TMP108_CONVERSION_TIME_MS); + tmp108->ready_time = ktime_add_ms(ktime_get(), + TMP108_CONVERSION_TIME_MS); err = devm_add_action_or_reset(dev, tmp108_restore_config, tmp108); if (err) { @@ -414,8 +410,8 @@ static int tmp108_resume(struct device *dev) err = regmap_update_bits(tmp108->regmap, TMP108_REG_CONF, TMP108_CONF_MODE_MASK, TMP108_MODE_CONTINUOUS); - tmp108->ready_time = get_jiffies_64() + - msecs_to_jiffies(TMP108_CONVERSION_TIME_MS); + tmp108->ready_time = ktime_add_ms(ktime_get(), + TMP108_CONVERSION_TIME_MS); return err; } -- 2.53.0