From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-x231.google.com (mail-it0-x231.google.com [IPv6:2607:f8b0:4001:c0b::231]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 73B0E21A16EC6 for ; Tue, 30 May 2017 03:12:53 -0700 (PDT) Received: by mail-it0-x231.google.com with SMTP id o5so38832007ith.1 for ; Tue, 30 May 2017 03:13:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=hxFxJGInLfBXwHkvs6pU8jcIamqXtOTRTUxvgLOQNGQ=; b=OwSE4QcBEzE22CnmzQm2iPoJ3MAUH56OxirxbRqNq/IBl8xmJQUkXMdHsYB+D0QDe8 aD8LF2ctYPW49ZBQ2MDf3dfLFk8Fj5EeMp1hEHmHyFlIKR195zC1DdEpPCO66+LZWVfI IzR8/d3+L5AOps+Eiz5G8GlRFFRjqAPNUCn7w= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=hxFxJGInLfBXwHkvs6pU8jcIamqXtOTRTUxvgLOQNGQ=; b=KjPUiDS9PRq8rkf2N4hr5m2XagIEOsEi/tMcV/sy8yFXpuGJTc0BaoEaZz0RB6fj3Q sFiyArA8VczIFTWnIgt4+PWOYUwGTMJFeJpMQ4/HgHTBbd5Czfcw4pBNr+fltC9iS0J3 U8gIJrhDX9JOVHRtrr/AHbu7Js7+EwKAm+aFnz+yCME6lK/GqrGFhSIbXULpc41LdtIn RCLUM/i8BrpCUjP55e13YoXqP+lL63XAPsekFxpukW0H/rLNOSgcJJ3A5XUgKPHlm3WY wLCYXM9BjiaLT+HmMwbWYpWLtzo7RAgOTRY+v7vkdM11o13Qfu7Toc3NX8ZSnfSAKzo+ dbVQ== X-Gm-Message-State: AODbwcCkZHoExVN/ZcfRtxEJOOf0Hrp0jJMPm47PoPnVplzajsZF2uvg M4+Lqgm5zCZvvRCkUYVYHulGowcU/LUJ X-Received: by 10.36.24.4 with SMTP id 4mr1182051itr.6.1496139231803; Tue, 30 May 2017 03:13:51 -0700 (PDT) MIME-Version: 1.0 Received: by 10.107.164.24 with HTTP; Tue, 30 May 2017 03:13:51 -0700 (PDT) In-Reply-To: References: <1495556147-6883-1-git-send-email-stelford@cadence.com> <20170526145029.GM32240@bivouac.eciton.net> From: Ard Biesheuvel Date: Tue, 30 May 2017 10:13:51 +0000 Message-ID: To: Scott Telford Cc: Leif Lindholm , "edk2-devel@lists.01.org" , "Tian, Feng" , "Zeng, Star" Subject: Re: [PATCH] Copy bus scanning workaround from ARM Juno PCIe driver. X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 30 May 2017 10:12:53 -0000 Content-Type: text/plain; charset="UTF-8" On 29 May 2017 at 16:14, Scott Telford wrote: >> From: Ard Biesheuvel [mailto:ard.biesheuvel@linaro.org] >> Sent: 26 May 2017 18:38 >> To: Leif Lindholm >> Cc: Scott Telford ; edk2-devel@lists.01.org > devel@ml01.01.org>; Tian, Feng ; Zeng, Star >> >> Subject: Re: [edk2] [PATCH] Copy bus scanning workaround from ARM Juno >> PCIe driver. > >> I'd still like to understand why this issue does not occur under >> Linux, or if it does occur, if we need an ECAM quirk for Juno to work >> around it. >> >> Could you give an example of which hardware combination triggers this >> issue? > > I don't have access to a Juno board here, so can't reproduce the original problem. It would certainly be interesting to know if the current Juno platform code using the generic PCIe driver suffers from the same problem or not. > > The platform I've been working with only exists within a Cadence emulation environment. I've seen the problem when testing an ASMedia ASM1182e bridge and an Intel I210 Ethernet card so it's probably not specific to certain PCIe bridges/devices. > > The original Juno PCIe driver (including the workaround) was committed by Olivier Martin at ARM, but I'm not sure if he's still there? > He used to maintain the ARM bits in Tianocore/EDK2 but he left ARM two years ago. > I'm working on moving the workaround into the PciExpressLib layer. > Yes, that is best for now.