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Miller" , Eric Dumazet , Jakub Kicinski , Jon Hunter , linux-arm-kernel@lists.infradead.org, linux-stm32@st-md-mailman.stormreply.com, Maxime Coquelin , netdev@vger.kernel.org, Paolo Abeni , Thierry Reding Subject: Re: [PATCH RFC net-next 2/5] net: stmmac: remove redundant racy tear-down in stmmac_dvr_remove() Message-ID: <20250228112840.00003e24@gmail.com> In-Reply-To: References: X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 27 Feb 2025 15:05:07 +0000 "Russell King (Oracle)" wrote: > While the network device is registered, it is published to userspace, > and thus userspace can change its state. This means calling > functions such as stmmac_stop_all_dma() and stmmac_mac_set() are > racy. > > Moreover, unregister_netdev() will unpublish the network device, and > then if appropriate call the .ndo_stop() method, which is > stmmac_release(). This will first call phylink_stop() which will > synchronously take the link down, resulting in stmmac_mac_link_down() > and stmmac_mac_set(, false) being called. > > stmmac_release() will also call stmmac_stop_all_dma(). > > Consequently, neither of these two functions need to called prior > to unregister_netdev() as that will safely call paths that will > result in this work being done if necessary. > > Remove these redundant racy calls. > > Signed-off-by: Russell King (Oracle) > Reviewed-by: Andrew Lunn > --- > drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > index 84d8b1c9f6d4..9462d05c40c8 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > @@ -7757,8 +7757,6 @@ void stmmac_dvr_remove(struct device *dev) > > pm_runtime_get_sync(dev); > > - stmmac_stop_all_dma(priv); > - stmmac_mac_set(priv, priv->ioaddr, false); > unregister_netdev(ndev); > > #ifdef CONFIG_DEBUG_FS We always build stmmac driver as built-in. Tried to build stmmac driver as a module, but some complicated dependencies were reported in our down-stream kernel :( I can not test this patch, so: Reviewed-by: Furong Xu <0x1207@gmail.com>