From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C54AC4332F for ; Wed, 8 Nov 2023 09:20:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235526AbjKHJUK (ORCPT ); Wed, 8 Nov 2023 04:20:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43638 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235475AbjKHJUJ (ORCPT ); Wed, 8 Nov 2023 04:20:09 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 83C0610A; Wed, 8 Nov 2023 01:20:07 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C56ACC433C7; Wed, 8 Nov 2023 09:20:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699435207; bh=cXx073rFQpuH5k631XKojmOybq3UcDQwzxYaqykG97E=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Ioxvr99r0Rtu6CEzJ4flkbU+DUiSQNXqPqQUT2ft/KHm6mghW/G0gtYz7zHtGvIo1 C3a5RMkl6GacIiHYNORYQWDL0/SPvK/jdJVPLWLy828aVYhJtBS+FmeyUrXWzAfmMR i7yxmLE+xd5iWbkZ1BfoRVn0KKz/1eoZpOfWWaXeo1ZOqueAesEjXZCHCOd9ivrU5n +pfe5N9DaXeW15SJGLBgK5SPagAcL680UNZEgLC470eVz57dRxudnvLRNwQu86A/TR lYb/7+Ba9bm0FmVNvlhJNBCP4ZCYccaFrSohjAm1tcFTdCN2gMIt96uSDaDTpscmGE k/snSZLE8wNVw== Date: Wed, 8 Nov 2023 10:20:04 +0100 From: Wolfram Sang To: Tam Nguyen Cc: linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, patches@amperecomputing.com, jarkko.nikula@linux.intel.com, andriy.shevchenko@linux.intel.com, mika.westerberg@linux.intel.com, jsd@semihalf.com, chuong@os.amperecomputing.com, darren@os.amperecomputing.com, stable@vger.kernel.org Subject: Re: [PATCH v2] i2c: designware: Disable TX_EMPTY irq while waiting for block length byte Message-ID: Mail-Followup-To: Wolfram Sang , Tam Nguyen , linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, patches@amperecomputing.com, jarkko.nikula@linux.intel.com, andriy.shevchenko@linux.intel.com, mika.westerberg@linux.intel.com, jsd@semihalf.com, chuong@os.amperecomputing.com, darren@os.amperecomputing.com, stable@vger.kernel.org References: <20231102033009.4555-1-tamnguyenchi@os.amperecomputing.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="3FWqOI7f1tKbk44/" Content-Disposition: inline In-Reply-To: <20231102033009.4555-1-tamnguyenchi@os.amperecomputing.com> Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org --3FWqOI7f1tKbk44/ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Nov 02, 2023 at 10:30:08AM +0700, Tam Nguyen wrote: > During SMBus block data read process, we have seen high interrupt rate > because of TX_EMPTY irq status while waiting for block length byte (the > first data byte after the address phase). The interrupt handler does not > do anything because the internal state is kept as STATUS_WRITE_IN_PROGRES= S. > Hence, we should disable TX_EMPTY IRQ until I2C DesignWare receives > first data byte from I2C device, then re-enable it to resume SMBus > transaction. >=20 > It takes 0.789 ms for host to receive data length from slave. > Without the patch, i2c_dw_isr() is called 99 times by TX_EMPTY interrupt. > And it is none after applying the patch. >=20 > Cc: stable@vger.kernel.org > Co-developed-by: Chuong Tran > Signed-off-by: Chuong Tran > Signed-off-by: Tam Nguyen Applied to for-current, thanks! --3FWqOI7f1tKbk44/ Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAmVLUsQACgkQFA3kzBSg KbY3mQ//TCqtokgPOJEAbu32xFeJt4qPYJPbmp2grGxCc/ThK8NU5YvjevMfYBfu iQB+nbHSgNpVXyzNK77YMDD7RNQBFnJgDpcvC6rXj8N8NaHThhAcEy+iGbDW37cI aA4eZ6xflK1nflWMu+LzFutfqNXEOLvbVGyrUb/e/aISn88DlHUyQCOrUVuBXRbp +sqrNr+P1GlP77hsZQwuomnNnIQKDeRhHNQTCqoGEbB7ddoZseCFpYXldTaIXJVY 8AUaBnBGZ6b9fDm7524DeoZJiErHLVWidb3clHyaSBR/yzehfd0ZdfktD+Xvs0L3 5tQ2BfrDCxzk3JHhG2dLWTGBdkP9KwEtftiFnszMjWPRaYnXGcqBeGMH+TOZyXgH UxzJvZLgiY59j1BkUDKftYUXSXuIh8sMcwnHYT4OhwpjGNyQx5JTr9saIPdWzcnD 9wtpPlK9E+a5NAh81rq9H10ODf97PnZyT9RoMRmEAZLo3DUxx1uM5qZ+q/eJbkjL cLXmQA5UAH3Er08bomNb4dPnWM6EWUruWKJJrg3ze8wUxFUp2R+vYK1RmHNbGuHQ m3pTlwvXbmSUZL/nBmJBSNbsscrmEvBPG4RWy+I+d6Q9e6+YYlabyPWTkdtqroyV RYmAKh3yL6CYPtBEWEwdh3Bm+R8642Euv7WBT7Fa9BrHQeshCsE= =t/rL -----END PGP SIGNATURE----- --3FWqOI7f1tKbk44/--