Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Tue, 2 Mar 2021 07:14:52 -0800
From:   Moritz Fischer <mdf@kernel.org>
To:     Lizhi Hou <lizhi.hou@xilinx.com>
Cc:     Tom Rix <trix@redhat.com>, linux-kernel@vger.kernel.org,
        linux-fpga@vger.kernel.org, maxz@xilinx.com,
        sonal.santan@xilinx.com, michal.simek@xilinx.com,
        stefanos@xilinx.com, devicetree@vger.kernel.org, mdf@kernel.org,
        robh@kernel.org, Max Zhen <max.zhen@xilinx.com>
Subject: Re: [PATCH V3 XRT Alveo 03/18] fpga: xrt: xclbin file helper
 functions
Message-ID: <YD5WbLCdCTBALQiI@epycbox.lan>
References: <20210218064019.29189-1-lizhih@xilinx.com>
 <20210218064019.29189-4-lizhih@xilinx.com>
 <4628ef05-27d1-b92f-9126-27a1f810c608@redhat.com>
 <3b73400c-cca1-60af-4eea-ed85de77a977@xilinx.com>
 <c79176af-8d0c-2300-3e4a-dfa604f10a62@redhat.com>
 <55ed0169-085c-9706-3b17-23ea582c43c3@xilinx.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <55ed0169-085c-9706-3b17-23ea582c43c3@xilinx.com>
Precedence: bulk

On Mon, Mar 01, 2021 at 04:25:37PM -0800, Lizhi Hou wrote:
> Hi Tom，
> 
> 
> On 02/28/2021 08:54 AM, Tom Rix wrote:
> > CAUTION: This message has originated from an External Source. Please use proper judgment and caution when opening attachments, clicking links, or responding to this email.
> > 
> > 
> > On 2/26/21 1:23 PM, Lizhi Hou wrote:
> > > Hi Tom,
> > > 
> > > 
> > snip
> > 
> > > > I also do not see a pragma pack, usually this is set of 1 so the compiler does not shuffle elements, increase size etc.
> > > This data structure is shared with other tools. And the structure is well defined with reasonable alignment. It is compatible with all compilers we have tested. So pragma pack is not necessary.
> > You can not have possibly tested all the configurations since the kernel supports many arches and compilers.
> > 
> > If the tested existing alignment is ok, pragma pack should be a noop on your tested configurations.
> > 
> > And help cover the untested configurations.
> Got it. I will add pragma pack(1).

Please do not use pragma pack(), add __packed to the structs in
question.

- Moritz