From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9578E372ED0; Sat, 12 Sep 2026 18:51:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789239115; cv=none; b=PSHddBAleIl8miYP8hwdn7zIrOlAeQGnTz4DiG+2P6ySaESZEf1G4DN3J40moGcZwWmqZov5ta1vCA9NknbJzDjMHOmN1uuwaT6yM2K16suL6X41Xtlxl9csYUQ9dfmLmvjTS3aDBRWw9lLyNIJruA607A2Bt5ROpL+ScIZg4MQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789239115; c=relaxed/simple; bh=CJLK6CywlkkD34Dho/BFXs5pENW7JjEJmm51hT23Rug=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mCARdnF+R4xgvQbsAVf4PPB6U+Fy9fVwW5fSaqs7VKVfWyyjPBY3vbb8HSlabkkfMU0cMCMnDPP0VgqrqcgvMzgkhEM8Hokp8hT8bqaConcVF4R0+xBUnTxHGJteoWg4G5Nd1miFoSnFYqdLBQ29q+wR0/D6DDO7iFuUHkFxhak= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ml5mVIIM; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ml5mVIIM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B35381F000FF; Sat, 12 Sep 2026 18:51:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789239114; bh=xp4IfAYehGX3fYN2IyitO9EFixTrwN/M1eGzQ5B04FI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ml5mVIIM82Cqe9fzMbb2zt0CZF0F0vE0+GB/XitBJMSgDC6K/idwpcaLyyFUxC0wV sclHI28nr4d4C3Ix+sFwpYJlEExQRZV2R0nuWvE3A5Lknx+rjxDCxD/bEpm8OGvpCe QZUIAnlPRIlbM05P1S1enmSKc+18D9h7e5y/8cfw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Babanpreet Singh , Sebastian Reichel , Sasha Levin Subject: [PATCH 5.15 600/935] power: supply: sbs-battery: Use a per-device serial number buffer Date: Sat, 12 Sep 2026 09:00:30 +0200 Message-ID: <20260912065540.602203562@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065526.833703348@linuxfoundation.org> References: <20260912065526.833703348@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Babanpreet Singh [ Upstream commit 6027892925b8d19d2245c2d077e2ae35b49cc2b1 ] sbs_get_battery_serial_number() formats the battery serial number into sbs_serial[], a single file-scope buffer shared by every sbs-battery instance, and points val->strval at it. Nothing restricts this driver to one instance. It binds per I2C client, and sbs-manager registers one muxed I2C channel per supported battery specifically so that the smart battery driver can be bound to each of them, so several sbs-battery instances on one system is a supported configuration. The power supply core reads strval after the driver's get_property() callback has returned: power_supply_show_property() fills a local union power_supply_propval, then formats it with sysfs_emit(). Two concurrent POWER_SUPPLY_PROP_SERIAL_NUMBER reads on different batteries therefore race for the shared buffer - battery B's sprintf() can land between battery A filling the buffer and the core reading it, and battery A then reports battery B's serial number. Move the buffer into struct sbs_info so that each battery formats into its own storage. It is deliberately not added to the chip->strings[] array: those entries hold the cached constant strings that sbs_invalidate_cached_props() clears on presence changes, whereas the serial number is re-read from its word register on every access. Fixes: d3ab61ecbab2 ("bq20z75: Add support for more power supply properties") Assisted-by: Claude:claude-opus-5 Signed-off-by: Babanpreet Singh Link: https://patch.msgid.link/20260726072206.7-2-bbnpreetsingh@gmail.com Signed-off-by: Sebastian Reichel Signed-off-by: Sasha Levin --- drivers/power/supply/sbs-battery.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/power/supply/sbs-battery.c b/drivers/power/supply/sbs-battery.c index a633130a768df..18f20a6b4a166 100644 --- a/drivers/power/supply/sbs-battery.c +++ b/drivers/power/supply/sbs-battery.c @@ -216,6 +216,7 @@ struct sbs_info { u32 flags; int technology; char strings[NR_STRING_BUFFERS][I2C_SMBUS_BLOCK_MAX + 1]; + char serial[5]; }; static char *sbs_get_string_buf(struct sbs_info *chip, @@ -820,18 +821,18 @@ static int sbs_get_battery_capacity(struct i2c_client *client, return 0; } -static char sbs_serial[5]; static int sbs_get_battery_serial_number(struct i2c_client *client, union power_supply_propval *val) { + struct sbs_info *chip = i2c_get_clientdata(client); int ret; ret = sbs_read_word_data(client, sbs_data[REG_SERIAL_NUMBER].addr); if (ret < 0) return ret; - sprintf(sbs_serial, "%04x", ret); - val->strval = sbs_serial; + sprintf(chip->serial, "%04x", ret); + val->strval = chip->serial; return 0; } -- 2.53.0