Received-SPF: pass (google.com: domain of linux-kernel+bounces-63982-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1;
Message-ID: <5476743f-3648-4038-97f8-a9df22c0f507@gmail.com>
Date: Tue, 13 Feb 2024 09:26:45 -0800
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH net-next] net: sparx5: Add spinlock for frame transmission
 from CPU
Content-Language: en-US
To: Horatiu Vultur <horatiu.vultur@microchip.com>, davem@davemloft.net,
 edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
 lars.povlsen@microchip.com, Steen.Hegelund@microchip.com,
 daniel.machon@microchip.com, UNGLinuxDriver@microchip.com
Cc: u.kleine-koenig@pengutronix.de, rmk+kernel@armlinux.org.uk,
 vladimir.oltean@nxp.com, jacob.e.keller@intel.com, yuehaibing@huawei.com,
 netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
 linux-kernel@vger.kernel.org
References: <20240213121705.4070598-1-horatiu.vultur@microchip.com>
From: Florian Fainelli <f.fainelli@gmail.com>
In-Reply-To: <20240213121705.4070598-1-horatiu.vultur@microchip.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit

On 2/13/24 04:17, Horatiu Vultur wrote:
> Both registers used when doing manual injection or fdma injection are
> shared between all the net devices of the switch. It was noticed that
> when having two process which each of them trying to inject frames on
> different ethernet ports, that the HW started to behave strange, by
> sending out more frames then expected. When doing fdma injection it is
> required to set the frame in the DCB and then make sure that the next
> pointer of the last DCB is invalid. But because there is no locks for
> this, then easily this pointer between the DCB can be broken and then it
> would create a loop of DCBs. And that means that the HW will
> continuously transmit these frames in a loop. Until the SW will break
> this loop.
> Therefore to fix this issue, add a spin lock for when accessing the
> registers for manual or fdma injection.
> 
> Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>

Any reason you targeted 'net-next' rather than 'net', as this appears to 
be clearly a bug fix here?
-- 
Florian