From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) (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 C087056E042; Tue, 8 Sep 2026 15:58:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788883105; cv=none; b=jORhHxemh6y72jO8nYbD4E3YIwlYxh9xv0UA6ONCJ1hlQR3z4t2I3FHZW4+lsWRPAheCZtrpl1D0ChiBWqijXjmX0P9GKeQXB69fCkzkFoBbBVHe8cFWKNlqznNHSG3leFDUyqzHNTHQ+dADusXsQKenY05/s9b1KvM9Noad1VA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788883105; c=relaxed/simple; bh=kUrLkyC+/QMgWXSK8kBjT7dW2PxhBp9WV247eIJFVNY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JsMcfVIrgX6TXriwDZFm+ZcT5mFszrU0o6gl+8RpVj4gcj/x8DrFCBEE0pf9Q0gUn5JjeQTYH84kQELiUcjgWl+kXH2ECgzEDPuDLsKxZ1ACBlI0VVQLTyu8g4T3om5zzF4Q3Oglmn2PyhXO7zI4hKEd0eFuV2lCoFXk0e2Jhdk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=YXxk2Ruc; arc=none smtp.client-ip=198.175.65.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="YXxk2Ruc" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1788883103; x=1820419103; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=kUrLkyC+/QMgWXSK8kBjT7dW2PxhBp9WV247eIJFVNY=; b=YXxk2RuctGASLDAnkcqQYKCQHCfxBPmDxRqEFpjn1unJDyMYlIxGkO1a IgB/9tT/oZx/YY9QUvmHQfmI8fpQizh7QSrHds0V+074vmnOAjM+OogN1 7sEquOptM1TDoC7CtqrIOzLNYS5/tHvrOENedzEetk/heWfRMgjuNNAU+ bCXXDGUpKaOwqgMgQ3UACpi4/kEI08gUuyEh4JkpzWiZrCXZoiAvBOXfZ mgTmzYLNxiJAsQ3ZjvAftjW2Tbm2lVCd7xfYO3gRo2kBOxfrKxyCAO2d7 Xr1JMVF2lL+kBXLbNCZqq2ug980F6HT+/A9Y/ugNYP9dFkzrSOC6jojPJ w==; X-CSE-ConnectionGUID: Ap7crcdbT76eS53QhAl5/g== X-CSE-MsgGUID: +3oO8/Y3Ti+b8HVTFS45pQ== X-IronPort-AV: E=McAfee;i="6800,10657,11900"; a="106660503" X-IronPort-AV: E=Sophos;i="6.25,269,1779174000"; d="scan'208";a="106660503" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Sep 2026 08:58:22 -0700 X-CSE-ConnectionGUID: 4f2Z7aI4R3GOjJ4ANUXnBg== X-CSE-MsgGUID: 8Qer96TlSL6Hq8q8RR6ebw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,269,1779174000"; d="scan'208";a="274841722" Received: from smoticic-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.244.92]) by orviesa004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Sep 2026 08:58:19 -0700 Date: Tue, 8 Sep 2026 18:58:17 +0300 From: Andy Shevchenko To: Yicong Yang Cc: ilpo.jarvinen@linux.intel.com, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, jirislaby@kernel.org, geshijian@picoheart.com, yangyang.8776@picoheart.com, yanligen@picoheart.com Subject: Re: [PATCH v3] serial: 8250_dw: Prefer SRBR in bogus RX timeout workaround if available Message-ID: References: <20260908141524.20302-1-yang.yicong@picoheart.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260908141524.20302-1-yang.yicong@picoheart.com> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Tue, Sep 08, 2026 at 10:15:24PM +0800, Yicong Yang wrote: > The DW uart could get into the cases where a bogus RX timeout > interrupt is asserted but no available data. This could be > workaround by doing a bogus read. > > Currently the driver's using the standard RBR (receive buffer > register) for this bogus read. However the reading of RBR > in this case is allowed to raise a hardware error if vendor > choose to implement in this way (our platform). It's also > allowed to do the bogus read using SRBR (shadow RBR) for > workaround which won't raise the hardware error. So change > to use the SRBR to workaround the issue if it's available. Okay now. Reviewed-by: Andy Shevchenko -- With Best Regards, Andy Shevchenko