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=1792530401; b=Mk5V/MBHPCjZiUbY6W8dgMEkFyx91zPJlM86lUyI/ATzJA3oJUHCdJFHB2vIPJ7hvn/G DSHy8Ho8lZDzIaaWrWNw4kgWyXDTlBfohiD2zkpb82JxnZtbXHJOil2M6OQkKCNJJJp8p +npO0FKqsA/Sbp8J48Cn1q2Msblla1H3RPCqx14tCcSlI52/zC1CFifTe1/Oo4XkzplCT PiGLYHzJLm2OonztfpnMblp36TSiGPTa2/t0rbNYJpayPdO0g6ScFWb8vHZQtEqw36giy ZyHVjDdAEXSHc/fMjIQBtOuHmYHkPfrBi2nbW4D6uCQ/u0r2R5h+vBntK7W77a1S+OQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792530401; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=eudeHbG6Q+7oXe06t43nAu8K28jSi/HhXLZbGMSKzy4=; b=h+FEn/GTepa+b5QRLIWqJU0eBHaT2m5UY9gTwXfhc6hM4TRk6Truzf4KV2dAZMYuzQLI 2kQmd3meTtum7G2YnbtRrIO1RhsTlkrydaYzZPLBiE30qvnMC+1VOHgd18NuLvBcenNHk eF7nm3ilW7TL99/FoR7iNVCxJohZ69b3wi4IRLB5qUWcDGwzDwZYN+weOAalAslpWm6of BCW0FS+oarTXyPtCShRdDdacaszmCWXznm9oM2+jd1aiOmlXUU0lGDkTYou2NyUQzzMPt 9pegd3ke5Sw2kfBX0tOMBmWhJdnZmBUd5I5UV90fHPm/TRWRkEaOdnf1ioYaweOeUYQ== 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=PzmzboAS; 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 8D051606A31A; Tue, 20 Oct 2026 21:06:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=PzmzboAS Received: by smtp.kernel.org (Postfix) with ESMTPSA id A19281F000C9; Tue, 20 Oct 2026 21:06:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792530401; bh=eudeHbG6Q+7oXe06t43nAu8K28jSi/HhXLZbGMSKzy4=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=PzmzboAS6hDP/7l5weoAm5lQEKQyO4t5TwvgWCLKsV13M+PmyHaPj96IQo+QmyTVH rqeRQ+wBalo6BcOc10zvMCbYJN+1zqLiut/Xy+hgzHNGBlWqaoRbBlbznw0hs6QNXN Kt+deUpQqtlWqBflW4vuXhZN2WghfP6Yw2K1D8amGa/iMfyFYFZqen3asmckyCPLqI 3rcLNOik2mcp1zfgCsFU6k09JWKWhXCMaZT0XFpquZ517wUOswwaOBRuGV4JfgUwrJ 2RbBglPmQc1PaqZ9pyP09b8PiC8q9PrZf/ddbsHhkR8nu3NziZerEIsT12N1hx/Mb1 KYnLuzqDgqotQ== Date: Tue, 20 Oct 2026 23:06:38 +0200 From: Andi Shyti To: Navon John Lukose Cc: Mika Westerberg , linux-i2c@vger.kernel.org, Andy Shevchenko , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] i2c: designware: size the RX FIFO threshold to the queued transfer Message-ID: References: <20261007191911.502428-1-navonjohnlukose@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-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261007191911.502428-1-navonjohnlukose@gmail.com> Hi Navon, please, don't forget to Cc the linux-i2c mailing list. On Thu, Oct 08, 2026 at 03:52:31AM +0530, Navon John Lukose wrote: > i2c_dw_xfer_msg() leaves DW_IC_RX_TL at the 0 that i2c_dw_configure_mode() > writes, so the controller raises RX_FULL once per received byte. Program > RX_TL from the reads already queued, capped at half the FIFO until the last > message is queued, so there is room for the rest. > > On an Arrow Lake-H LPSS core with rx_fifo_depth 32, a 22-byte HID input > report costs 2.00 interrupts instead of 21.43, and a 452-byte descriptor > 0.14 interrupts per byte instead of 1.64. Polling the touchpad with > HIDIOCGINPUT at 142 Hz draws 1.58 W less platform power (psys, 32 paired > runs). > > Acked-by: Mika Westerberg > Assisted-by: LLM > Signed-off-by: Navon John Lukose pushed to i2c/i2c-2. Thanks, Andi