Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <2825f1ab-5d53-6912-f5ba-0bff9709e387@microchip.com>
Date:   Fri, 23 Jun 2023 17:42:33 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.11.0
Subject: Re: net: macb: sparse warning fixes
Content-Language: en-US
To:     Andrew Lunn <andrew@lunn.ch>
CC:     Ben Dooks <ben.dooks@codethink.co.uk>, <netdev@vger.kernel.org>,
        <pabeni@redhat.com>, <kuba@kernel.org>, <edumazet@google.com>,
        <davem@davemloft.net>, <linux-kernel@vger.kernel.org>,
        <claudiu.beznea@microchip.com>
References: <20230622130507.606713-1-ben.dooks@codethink.co.uk>
 <66f00ffc-571b-86b3-5c35-b9ce566cc149@microchip.com>
 <fe335672-6b8d-4fb0-81ce-34f029891d39@lunn.ch>
From:   Nicolas Ferre <nicolas.ferre@microchip.com>
Organization: microchip
In-Reply-To: <fe335672-6b8d-4fb0-81ce-34f029891d39@lunn.ch>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 23/06/2023 at 17:38, Andrew Lunn wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> On Fri, Jun 23, 2023 at 03:16:23PM +0200, Nicolas Ferre wrote:
>> Hi Ben,
>>
>> On 22/06/2023 at 15:05, Ben Dooks wrote:
>>> These are 3 hopefully easy patches for fixing sparse errors due to
>>> endian-ness warnings. There are still some left, but there are not
>>> as easy as they mix host and network fields together.
>>>
>>> For example, gem_prog_cmp_regs() has two u32 variables that it does
>>> bitfield manipulation on for the tcp ports and these are __be16 into
>>> u32, so not sure how these are meant to be changed. I've also no hardware
>>> to test on, so even if these did get changed then I can't check if it is
>>> working pre/post change.
>>
>> Do you know if there could be any impact on performance (even if limited)?
> 
> Hi Nicolas
> 
> This is inside a netdev_dbg(). So 99% of the time it is compiled
> out. The other 1% of the time, your 115200 baud serial port is
> probably the bottleneck, not an endianness swap.

Yeah, sure thing: I was not talking about the 3/3 patch where, yes, 
indeed it doesn't have an importance.

Others in gem_enable_flow_filters() and gem_prog_cmp_regs() look like 
they are away from hot path anyway, so here again probably no impact.

Regards,
   Nicolas

-- 
Nicolas Ferre