From: Arnd Bergmann <arnd@arndb.de>
To: LABBE Corentin <clabbe.montjoie@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org, robh+dt@kernel.org,
mark.rutland@arm.com, maxime.ripard@free-electrons.com,
wens@csie.org, linux@armlinux.org.uk, davem@davemloft.net,
devicetree@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com
Subject: Re: [PATCH v2 1/5] ethernet: add sun8i-emac driver
Date: Fri, 29 Jul 2016 11:26:57 +0200 [thread overview]
Message-ID: <4552489.XcKoxjnXeP@wuerfel> (raw)
In-Reply-To: <20160728131826.GA7582@Red>
On Thursday, July 28, 2016 3:18:26 PM CEST LABBE Corentin wrote:
>
> I will reworked locking and it seems that no locking is necessary.
> I have added the following comment about the locking strategy:
>
> /* Locking strategy:
> * RX queue does not need any lock since only sun8i_emac_poll() access it.
> * (All other RX modifiers (ringparam/ndo_stop) disable NAPI and so sun8i_emac_poll())
> * TX queue is handled by sun8i_emac_xmit(), sun8i_emac_complete_xmit() and sun8i_emac_tx_timeout()
> * (All other RX modifiers (ringparam/ndo_stop) disable NAPI and stop queue)
> *
> * sun8i_emac_xmit() could fire only once (netif_tx_lock)
> * sun8i_emac_complete_xmit() could fire only once (called from NAPI)
> * sun8i_emac_tx_timeout() could fire only once (netif_tx_lock) and couldnt
> * race with sun8i_emac_xmit (due to netif_tx_lock) and with sun8i_emac_complete_xmit which disable NAPI.
> *
> * So only sun8i_emac_xmit and sun8i_emac_complete_xmit could fire at the same time.
> * But they never could modify the same descriptors:
> * - sun8i_emac_complete_xmit() will modify only descriptors with empty status
> * - sun8i_emac_xmit() will modify only descriptors set to DCLEAN
> * Proper memory barriers ensure that descriptor set to DCLEAN could not be
> * modified latter by sun8i_emac_complete_xmit().
> * */
Sounds good, the comment is certainly very helpful here.
Arnd
WARNING: multiple messages have this Message-ID (diff)
From: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
To: LABBE Corentin <clabbe.montjoie-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
mark.rutland-5wv7dgnIgG8@public.gmane.org,
maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org,
wens-jdAy2FN1RRM@public.gmane.org,
linux-I+IVW8TIWO2tmTQ+vhA3Yw@public.gmane.org,
davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org,
devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
Subject: Re: [PATCH v2 1/5] ethernet: add sun8i-emac driver
Date: Fri, 29 Jul 2016 11:26:57 +0200 [thread overview]
Message-ID: <4552489.XcKoxjnXeP@wuerfel> (raw)
In-Reply-To: <20160728131826.GA7582@Red>
On Thursday, July 28, 2016 3:18:26 PM CEST LABBE Corentin wrote:
>
> I will reworked locking and it seems that no locking is necessary.
> I have added the following comment about the locking strategy:
>
> /* Locking strategy:
> * RX queue does not need any lock since only sun8i_emac_poll() access it.
> * (All other RX modifiers (ringparam/ndo_stop) disable NAPI and so sun8i_emac_poll())
> * TX queue is handled by sun8i_emac_xmit(), sun8i_emac_complete_xmit() and sun8i_emac_tx_timeout()
> * (All other RX modifiers (ringparam/ndo_stop) disable NAPI and stop queue)
> *
> * sun8i_emac_xmit() could fire only once (netif_tx_lock)
> * sun8i_emac_complete_xmit() could fire only once (called from NAPI)
> * sun8i_emac_tx_timeout() could fire only once (netif_tx_lock) and couldnt
> * race with sun8i_emac_xmit (due to netif_tx_lock) and with sun8i_emac_complete_xmit which disable NAPI.
> *
> * So only sun8i_emac_xmit and sun8i_emac_complete_xmit could fire at the same time.
> * But they never could modify the same descriptors:
> * - sun8i_emac_complete_xmit() will modify only descriptors with empty status
> * - sun8i_emac_xmit() will modify only descriptors set to DCLEAN
> * Proper memory barriers ensure that descriptor set to DCLEAN could not be
> * modified latter by sun8i_emac_complete_xmit().
> * */
Sounds good, the comment is certainly very helpful here.
Arnd
WARNING: multiple messages have this Message-ID (diff)
From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 1/5] ethernet: add sun8i-emac driver
Date: Fri, 29 Jul 2016 11:26:57 +0200 [thread overview]
Message-ID: <4552489.XcKoxjnXeP@wuerfel> (raw)
In-Reply-To: <20160728131826.GA7582@Red>
On Thursday, July 28, 2016 3:18:26 PM CEST LABBE Corentin wrote:
>
> I will reworked locking and it seems that no locking is necessary.
> I have added the following comment about the locking strategy:
>
> /* Locking strategy:
> * RX queue does not need any lock since only sun8i_emac_poll() access it.
> * (All other RX modifiers (ringparam/ndo_stop) disable NAPI and so sun8i_emac_poll())
> * TX queue is handled by sun8i_emac_xmit(), sun8i_emac_complete_xmit() and sun8i_emac_tx_timeout()
> * (All other RX modifiers (ringparam/ndo_stop) disable NAPI and stop queue)
> *
> * sun8i_emac_xmit() could fire only once (netif_tx_lock)
> * sun8i_emac_complete_xmit() could fire only once (called from NAPI)
> * sun8i_emac_tx_timeout() could fire only once (netif_tx_lock) and couldnt
> * race with sun8i_emac_xmit (due to netif_tx_lock) and with sun8i_emac_complete_xmit which disable NAPI.
> *
> * So only sun8i_emac_xmit and sun8i_emac_complete_xmit could fire at the same time.
> * But they never could modify the same descriptors:
> * - sun8i_emac_complete_xmit() will modify only descriptors with empty status
> * - sun8i_emac_xmit() will modify only descriptors set to DCLEAN
> * Proper memory barriers ensure that descriptor set to DCLEAN could not be
> * modified latter by sun8i_emac_complete_xmit().
> * */
Sounds good, the comment is certainly very helpful here.
Arnd
next prev parent reply other threads:[~2016-07-29 9:27 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-20 8:03 [PATCH v2 0/5] net-next: ethernet: add sun8i-emac driver LABBE Corentin
2016-07-20 8:03 ` LABBE Corentin
2016-07-20 8:03 ` LABBE Corentin
2016-07-20 8:03 ` [PATCH v2 1/5] " LABBE Corentin
2016-07-20 8:03 ` LABBE Corentin
2016-07-20 8:03 ` LABBE Corentin
2016-07-20 9:56 ` Arnd Bergmann
2016-07-20 9:56 ` Arnd Bergmann
2016-07-20 9:56 ` Arnd Bergmann
2016-07-28 13:18 ` LABBE Corentin
2016-07-28 13:18 ` LABBE Corentin
2016-07-28 13:18 ` LABBE Corentin
2016-07-29 9:26 ` Arnd Bergmann [this message]
2016-07-29 9:26 ` Arnd Bergmann
2016-07-29 9:26 ` Arnd Bergmann
2016-07-25 19:54 ` Maxime Ripard
2016-07-25 19:54 ` Maxime Ripard
2016-07-25 19:54 ` Maxime Ripard
2016-07-28 14:57 ` LABBE Corentin
2016-07-28 14:57 ` LABBE Corentin
2016-07-28 14:57 ` LABBE Corentin
2016-07-29 17:25 ` Maxime Ripard
2016-07-29 17:25 ` Maxime Ripard
2016-07-29 17:25 ` Maxime Ripard
2016-07-30 1:30 ` Chen-Yu Tsai
2016-07-30 1:30 ` Chen-Yu Tsai
2016-07-30 1:30 ` Chen-Yu Tsai
2016-07-30 7:34 ` Maxime Ripard
2016-07-30 7:34 ` Maxime Ripard
2016-07-30 7:34 ` Maxime Ripard
2016-07-29 10:12 ` Andre Przywara
2016-07-29 10:12 ` Andre Przywara
2016-07-29 10:12 ` Andre Przywara
2016-08-24 12:02 ` LABBE Corentin
2016-08-24 12:02 ` LABBE Corentin
2016-08-24 12:02 ` LABBE Corentin
2016-08-26 20:49 ` Maxime Ripard
2016-08-26 20:49 ` Maxime Ripard
2016-08-26 20:49 ` Maxime Ripard
2016-07-20 8:03 ` [PATCH v2 2/5] MAINTAINERS: Add myself as maintainers of sun8i-emac LABBE Corentin
2016-07-20 8:03 ` LABBE Corentin
2016-07-20 8:03 ` LABBE Corentin
2016-07-20 8:03 ` [PATCH v2 3/5] ARM: sun8i: dt: Add DT bindings documentation for Allwinner sun8i-emac LABBE Corentin
2016-07-20 8:03 ` LABBE Corentin
2016-07-20 8:03 ` LABBE Corentin
2016-07-20 19:15 ` Rob Herring
2016-07-20 19:15 ` Rob Herring
2016-07-20 19:15 ` Rob Herring
2016-07-28 13:21 ` LABBE Corentin
2016-07-28 13:21 ` LABBE Corentin
2016-07-28 13:21 ` LABBE Corentin
2016-07-21 7:55 ` Maxime Ripard
2016-07-21 7:55 ` Maxime Ripard
2016-07-21 7:55 ` Maxime Ripard
2016-07-28 13:40 ` LABBE Corentin
2016-07-28 13:40 ` LABBE Corentin
2016-07-28 13:40 ` LABBE Corentin
2016-07-28 18:49 ` Maxime Ripard
2016-07-28 18:49 ` Maxime Ripard
2016-07-28 18:49 ` Maxime Ripard
2016-07-29 8:15 ` LABBE Corentin
2016-07-29 8:15 ` LABBE Corentin
2016-07-29 8:15 ` LABBE Corentin
2016-07-29 18:12 ` Maxime Ripard
2016-07-29 18:12 ` Maxime Ripard
2016-07-29 18:12 ` Maxime Ripard
2016-07-20 8:03 ` [PATCH v2 4/5] ARM: dts: sun8i-h3: add sun8i-emac ethernet driver LABBE Corentin
2016-07-20 8:03 ` LABBE Corentin
2016-07-20 8:03 ` LABBE Corentin
2016-07-20 8:03 ` [PATCH v2 5/5] ARM: dts: sun8i: Enable sun8i-emac on the Orange PI PC LABBE Corentin
2016-07-20 8:03 ` LABBE Corentin
2016-07-20 8:03 ` LABBE Corentin
2016-07-25 13:16 ` [PATCH v2 0/5] net-next: ethernet: add sun8i-emac driver paulo
2016-07-25 13:16 ` paulo at inutilfutil.com
2016-07-25 13:16 ` paulo
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