From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: Re: [PATCH net-next-2.6 v8 01/20] CAN : Add flow control processing. Date: Sun, 12 Dec 2010 16:26:06 +0100 Message-ID: <4D04E98E.5090800@pengutronix.de> References: <4CFE13E4.2020707@dsn.okisemi.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============6957107330546993352==" Cc: andrew.chih.howe.khor-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, qi.wang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, margie.foster-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, yong.y.wang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org, kok.howg.ewe-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, joel.clark-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, Wolfgang Grandegger To: Tomoya MORINAGA Return-path: In-Reply-To: <4CFE13E4.2020707-ECg8zkTtlr0C6LszWs/t0g@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: socketcan-core-bounces-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org Errors-To: socketcan-core-bounces-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org List-Id: netdev.vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --===============6957107330546993352== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig779C94C24F67452167BA05DC" This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig779C94C24F67452167BA05DC Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 12/07/2010 12:00 PM, Tomoya MORINAGA wrote: > Currently, there is no flow control processing. > Thus, Add flow control processing as > when there is no empty of tx buffer, > netif_stop_queue is called. > When there is empty buffer, netif_wake_queue is called. See comment inline. > Signed-off-by: Tomoya MORINAGA > --- > drivers/net/can/pch_can.c | 31 ++++++++++++------------------- > 1 files changed, 12 insertions(+), 19 deletions(-) >=20 > diff --git a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c > index a9b6a65..f0f1404 100644 > --- a/drivers/net/can/pch_can.c > +++ b/drivers/net/can/pch_can.c > @@ -102,6 +102,10 @@ > =20 > #define PCH_FIFO_THRESH 16 > =20 > +/* TxRqst2 show status of MsgObjNo.17~32 */ > +#define PCH_TREQ2_TX_MASK (((1 << PCH_TX_OBJ_NUM) - 1) <<\ > + (PCH_RX_OBJ_END - 16)) > + > enum pch_ifreg { > PCH_RX_IFREG, > PCH_TX_IFREG, > @@ -871,6 +875,8 @@ MSG_OBJ: > dlc =3D 8; > stats->tx_bytes +=3D dlc; > stats->tx_packets++; > + if (int_stat =3D=3D PCH_TX_OBJ_END) > + netif_wake_queue(ndev); > } > =20 > int_stat =3D pch_can_int_pending(priv); > @@ -1009,18 +1015,6 @@ static int pch_close(struct net_device *ndev) > return 0; > } > =20 > -static int pch_get_msg_obj_sts(struct net_device *ndev, u32 obj_id) > -{ > - u32 buffer_status =3D 0; > - struct pch_can_priv *priv =3D netdev_priv(ndev); > - > - /* Getting the message object status. */ > - buffer_status =3D (u32) pch_can_get_buffer_status(priv); > - > - return buffer_status & obj_id; > -} > - > - > static netdev_tx_t pch_xmit(struct sk_buff *skb, struct net_device *nd= ev) > { > int i, j; > @@ -1031,17 +1025,16 @@ static netdev_tx_t pch_xmit(struct sk_buff *skb= , struct net_device *ndev) > if (can_dropped_invalid_skb(ndev, skb)) > return NETDEV_TX_OK; > =20 > - if (priv->tx_obj =3D=3D PCH_TX_OBJ_END) { /* Point tail Obj */ > - while (pch_get_msg_obj_sts(ndev, (((1 << PCH_TX_OBJ_NUM)-1) << > - PCH_RX_OBJ_NUM))) > - udelay(500); > + if (priv->tx_obj =3D=3D PCH_TX_OBJ_END) { > + if (ioread32(&priv->regs->treq2) & PCH_TREQ2_TX_MASK) > + netif_stop_queue(ndev); David asked you in his previous review to implement a pure software solution without relying on the hardware because it tends to be racy. > =20 > - priv->tx_obj =3D PCH_TX_OBJ_START; /* Point head of Tx Obj ID */ > - tx_buffer_avail =3D priv->tx_obj; /* Point Tail of Tx Obj */ > + tx_buffer_avail =3D priv->tx_obj; > + priv->tx_obj =3D PCH_TX_OBJ_START; > } else { > tx_buffer_avail =3D priv->tx_obj; > + priv->tx_obj++; > } > - priv->tx_obj++; > =20 > /* Reading the Msg Obj from the Msg RAM to the Interface register. */= > iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[1].cmask); cheers, Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | --------------enig779C94C24F67452167BA05DC Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk0E6ZEACgkQjTAFq1RaXHOkfQCfYOcWycuoEAr7Uw0+WHk9gMl1 H3gAnjbrhyelv3OHgGbx/4+tRRgejrVL =viGG -----END PGP SIGNATURE----- --------------enig779C94C24F67452167BA05DC-- --===============6957107330546993352== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Socketcan-core mailing list Socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org https://lists.berlios.de/mailman/listinfo/socketcan-core --===============6957107330546993352==--