From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.49 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794583932; b=jOaEqwdlaIZL0VZ0O1fdxutadQJE7N5G0wkRkT6377Q9osSyQ90sid3W7TLNcdTdmDIV B69vI8iMxxDMdScyRv53+O1PFuaqrQtwRx46bIdLeSwWwCHalf+ITZWS/5dCqMuYz5Gum f/r5tukNfbnLY/WeYZtiZxg7zsv5SxRfmlD1coQugQp4DN81GDWyxAKNBka0AGVcpF4Le OLRp4ERje7+lxRVxXkVD2uh8qXTjVMqaaloi7O8P5GKemMWVx4689X5drAfxw+cadC4Kd b5f4AfWbMjWKiItjEbfhU+EJTXnRlr5/hnBFGNrTQOPIi2nJ57X9nOnH0iR7ri2endg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794583932; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:Date:Subject:MIME-Version: Content-Type:Content-Transfer-Encoding:Message-Id:References: In-Reply-To:To:Cc:X-Mailer; bh=+AF8rxrVs5leS4swff53I33rqYcRZ3ybrAATN/A0bvc=; b=o14G22COzRSYvtEAjg92Kp6qqhMBOIcwTnpiKNrXNsE2WA/4E5EG4AZPuiA1zGjL/NYE yOZMyTiIDplP7Fo96/UF7qAblmYr0/g4ZBFwEo+R1IfFpB2snT1jXqzCJ7WzQO4xLaECj qaoSq69/XxYkRHAWvyIZ+c1DKYfoQitS04NDM14xHUYoHcO9+YfQm0rzi+S6eh2DgzthK KLapMzyu9gh/TGy2aCcnANxExXe7AucLvipHgkvIdjH0AKbqCm4C4fylXBZaPRgHgBElI ql7xGuZ+8GYIyk0+MKnmAN1LVrhu76pkZsGOoLPKga/3JVyQ5kA1V+tz/We5w1PSw4g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=EczKAdfS; arc=none smtp.remote-ip=91.218.175.49 Received: from mta0.migadu.com (out-49.mta0.migadu.com [91.218.175.49]) (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 DE7FE606A337 for ; Fri, 13 Nov 2026 15:32:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org DE7FE606A337 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=EczKAdfS X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=h9vDUcTlFuZv+2e04iwT1Nc5kh2/0YVX+hNUDjF9CFs=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1794583930; v=1; x=1795188730; b=EczKAdfSPltWxI8Q+E4I9tdXwY3q/iE99vqBkcooj/HVM/fus0YlS7ihYOy8iI/fPKL6PdDj cOf8FU5M1pLI7WQz/0chgSgC9sMw08HdnqZzx6Aq3P2GLFU6uBkOQFk9zktmyMZAHsn0YcCvn8B 5+KalmGuOiJCRrfQqfiCKcyI= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 7149c44fd578d60a; Fri, 13 Nov 2026 15:32:10 +0000 X-Mizu-Trace-ID: 7149c44fd578d60a X-Migadu-Flow: FLOW_OUT From: Peng Fan Date: Fri, 13 Nov 2026 23:31:50 +0800 Subject: [PATCH v2 02/10] regmap-i2c: keep bus raw write limit when applying read quirk 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-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261113-regmap-improve-v2-2-5dfd6a89078f@nxp.com> References: <20261113-regmap-improve-v2-0-5dfd6a89078f@nxp.com> In-Reply-To: <20261113-regmap-improve-v2-0-5dfd6a89078f@nxp.com> To: Mark Brown , Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , Johan Hovold , Lucas Tanure Cc: linux-kernel@vger.kernel.org, driver-core@lists.linux.dev, Peng Fan X-Mailer: b4 0.14.3 From: Peng Fan regmap_get_i2c_bus() applies adapter quirks on top of the raw I/O limits advertised by the selected bus, but it starts from zero-initialised local variables and then overwrites both max_raw_read and max_raw_write of the copied bus. If only one direction is clamped by the adapter, the limit of the other direction is dropped. For example, regmap_i2c_smbus_i2c_block sets a 31-byte limit for both directions. An adapter that only reports max_read_len causes the copied bus to advertise 31 bytes for reads and no limit for writes, even though I2C_SMBUS_BLOCK_MAX - 1 still applies. Seed the locals from the selected bus and only replace a limit when the adapter quirk is more restrictive. Also only allocate the bus copy when one of the limits actually changes. Fixes: ea030ca68819 ("regmap-i2c: Set regmap max raw r/w from quirks") Signed-off-by: Peng Fan --- drivers/base/regmap/regmap-i2c.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/base/regmap/regmap-i2c.c b/drivers/base/regmap/regmap-i2c.c index 51a04961faf7..8663a4ec0a3d 100644 --- a/drivers/base/regmap/regmap-i2c.c +++ b/drivers/base/regmap/regmap-i2c.c @@ -353,7 +353,7 @@ static const struct regmap_bus *regmap_get_i2c_bus(struct i2c_client *i2c, const struct i2c_adapter_quirks *quirks; const struct regmap_bus *bus = NULL; struct regmap_bus *ret_bus; - u16 max_read = 0, max_write = 0; + u16 max_read, max_write; if (i2c_check_functionality(i2c->adapter, I2C_FUNC_I2C)) bus = ®map_i2c; @@ -391,18 +391,22 @@ static const struct regmap_bus *regmap_get_i2c_bus(struct i2c_client *i2c, if (!bus) return ERR_PTR(-ENOTSUPP); + max_read = bus->max_raw_read; + max_write = bus->max_raw_write; + quirks = i2c->adapter->quirks; if (quirks) { if (quirks->max_read_len && - (bus->max_raw_read == 0 || bus->max_raw_read > quirks->max_read_len)) + (max_read == 0 || max_read > quirks->max_read_len)) max_read = quirks->max_read_len; if (quirks->max_write_len && - (bus->max_raw_write == 0 || bus->max_raw_write > quirks->max_write_len)) + (max_write == 0 || max_write > quirks->max_write_len)) max_write = quirks->max_write_len - (config->reg_bits + config->pad_bits) / BITS_PER_BYTE; - if (max_read || max_write) { + if (max_read != bus->max_raw_read || + max_write != bus->max_raw_write) { ret_bus = kmemdup(bus, sizeof(*bus), GFP_KERNEL); if (!ret_bus) return ERR_PTR(-ENOMEM); -- 2.56.0