From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f51.google.com (mail-pj1-f51.google.com [209.85.216.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3035E376BC6 for ; Sun, 26 Jul 2026 07:22:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785050530; cv=none; b=YI6NJ6TOX7LD+KQ1RaeD3SNhPLaQ3x+TgSqDYoTsc9d2OdQa3OMAYz6NLULMNtUBI+UXksN0hwytQKryX8RzyC9QrpWS8Q4AqP1x2K1x+YqywKp1Z7RH1z9YNE+VjDWDT/w320QtTuZYb8PouoktDizXb2fO8trLpQqu0iiPlhw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785050530; c=relaxed/simple; bh=VZqa9XeAd4NhX6cM73mF0bLWzPvOZixViX26jECVjuQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=e4BSO093ulwZVtwNh2p7nFHKE1W2whvOSHtSnozQDqej+ADBw1gaPntCKSkHliC9UvDM2moK+Qq/402vrVD5JcF/ACuIUV8LiW+FrQHJH7bgnDDFzI7EFHpQoed08RXoCUi6LifZMAwTvm2hG1NLRNaE8+wvzLRI+cvr03668UY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Qbf2Abjk; arc=none smtp.client-ip=209.85.216.51 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.b="Qbf2Abjk" Received: by mail-pj1-f51.google.com with SMTP id 98e67ed59e1d1-38dcbade417so1837163a91.1 for ; Sun, 26 Jul 2026 00:22:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1785050528; x=1785655328; 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=CjR+vy5fTEU4JTVfRNyKayBUu5r66+FapJQWGGIffo0=; b=Qbf2AbjkAAjrPll47sXx2gEXU2rZ4R4mAP5wqRrWDnMMRXXFyPf0p4m1DxJVrZ6S7t lyvyGe7YQHb9vGLrsU+3EE5q3QJ07LH0wygdQvqHwz1/2JBPqYcMKkZBH9w6J1OHQOA8 0VdsfbA6d2YXUWM5c9GFJXovdh6MsQZi0oo8z1m2fSemrw9/u9JoQ/Np8WFUvms5K+af s64rdZpZcMzILLx6b39Irt9wSrSeHM0601Jce2OlPtK1eiS91uhwAYzUYxtsY0CZgjZY RwiThq0GKezUcq4JmGFfiRkXS4zj0a/SGVQkSx7C1Z4G23zTk6W62SVP3NEwqbWUJ8GM uw0Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785050528; x=1785655328; 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=CjR+vy5fTEU4JTVfRNyKayBUu5r66+FapJQWGGIffo0=; b=ggm0ywy4Z6H6ITNn1/cnmdkymM+zsEN9zFwiYDtYZ8DQV8y6qkB8jitnPU6eI85mmX YOmv9noKrptSm4kavpcA+g9wX6zNldvm5lzzzCKc97+dvJrsNh8CI79ijYlyvBQ7Pd03 hPr5jTTbiHB/IMK+3GuHzdyNY5ch0LUE4R9niW0E9JfNx3mejqzB+agOmym8wJpcOU9H tfVm9fpYMZme93/GD6kK/rUmGjFBXzroUfQM0OLL37F97AAlJKd4ZTuhCRJokZKM/ZPg 2KizTKkykBbwnft3uJBG3CZ+29syAfIVmvP2xZUi9JebKNtdmjLxqzDkXOjWqh3DuniH SGXQ== X-Forwarded-Encrypted: i=1; AHgh+RrgkqlaHC7N/azY3rSXBTg16jme5oSJEur56MNmm9unziJCgR+NiVhhbADTrQl5Dat/WHufYBpqvuqW7tQ=@vger.kernel.org X-Gm-Message-State: AOJu0Yx1a843rIUO0+Hhi5q/KIzWNWXUiRiUDfW0Bt9I46GMlykT4vRQ YT1X5b12OXwSbgUG87tWcFLRY8gapiBQ9Mnrd6QSqpUy/mpQNJ+k/C9Q X-Gm-Gg: AR+sD1062gZyBDakJGl07smJL2AT42uEFxNIg1ixOywsEX2ukEl0Jls30Kmi/XR0HfU BybqVHAHw1AhAN2j37AYOIGl5zHIgBF7O1GcEk5BYEzU6kq4KNC21XB0oXk1jtbUjDJPxr3XB04 OJKLbQn3q5SdbWtU4tTVLtHS3fAFd4Nb2BNYhOv+YNFTwd8m8vsZFk0q8hPNi5DePnRLT3Ll+zp tmtaWIJfe8u8Kz5KXbjZMt1diZun/HdiTVFCFHBkq8mwacWSoHpPHAV8AloO+1m352mcYgqPZe0 VH1MMzsVTeqXbblafb/g/sryBixXQlmvyGaZFAmB/M3GVRzwHwL4znDNnvuQS5DyKNZ3EylLSFe 6n5oI+rvMUCg/rREKpUiwAen1z/rqGuObwFRCy8XCha0oltolCmZcLGJ2vhGlRPVjqKpOCWBIIv SWzw== X-Received: by 2002:a17:90b:17cd:b0:38d:dfd1:7c1 with SMTP id 98e67ed59e1d1-38f293cf2ddmr4553457a91.2.1785050528186; Sun, 26 Jul 2026 00:22:08 -0700 (PDT) Received: from kdev.. ([108.180.130.139]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-38f294e1ab1sm1489074a91.10.2026.07.26.00.22.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 26 Jul 2026 00:22:07 -0700 (PDT) From: Babanpreet Singh To: Sebastian Reichel Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Babanpreet Singh Subject: [PATCH 1/2] power: supply: sbs-battery: Use a per-device serial number buffer Date: Sun, 26 Jul 2026 07:22:05 +0000 Message-ID: <20260726072206.7-2-bbnpreetsingh@gmail.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260726072206.7-1-bbnpreetsingh@gmail.com> References: <20260726072206.7-1-bbnpreetsingh@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 --- 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 017ec06be766..9bdb6c599c5f 100644 --- a/drivers/power/supply/sbs-battery.c +++ b/drivers/power/supply/sbs-battery.c @@ -217,6 +217,7 @@ 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, @@ -821,18 +822,18 @@ 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; } -- 2.43.0