From: Joakim Zhang <qiangqing.zhang@nxp.com>
To: Marc Kleine-Budde <mkl@pengutronix.de>, Michael Walle <michael@walle.cc>
Cc: "linux-can@vger.kernel.org" <linux-can@vger.kernel.org>,
dl-linux-imx <linux-imx@nxp.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: RE: [PATCH linux-can-next/flexcan] can: flexcan: fix TDC feature
Date: Wed, 16 Sep 2020 02:26:52 +0000 [thread overview]
Message-ID: <DB8PR04MB6795D75BE5A285980E75892EE6210@DB8PR04MB6795.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <61489f52-84d5-e800-02f9-e40596e269ef@pengutronix.de>
> -----Original Message-----
> From: Marc Kleine-Budde <mkl@pengutronix.de>
> Sent: 2020年9月16日 6:16
> To: Joakim Zhang <qiangqing.zhang@nxp.com>; Michael Walle
> <michael@walle.cc>
> Cc: linux-can@vger.kernel.org; dl-linux-imx <linux-imx@nxp.com>;
> netdev@vger.kernel.org
> Subject: Re: [PATCH linux-can-next/flexcan] can: flexcan: fix TDC feature
>
> On 6/30/20 4:25 AM, Joakim Zhang wrote:
> > I have also noticed this difference, although this could not break
> > function, but IMO, using priv->can.ctrlmode should be better.
> >
[...]
> > 2) Clean timing register.
> > --- a/drivers/net/can/flexcan.c
> > +++ b/drivers/net/can/flexcan.c
> > @@ -1167,6 +1167,14 @@ static void flexcan_set_bittiming_cbt(const
> struct net_device *dev)
> > struct flexcan_regs __iomem *regs = priv->regs;
> > u32 reg_cbt, reg_fdctrl;
> >
> > + reg_cbt = priv->read(®s->cbt);
> > + reg_cbt &= ~(FLEXCAN_CBT_BTF |
> > + FIELD_PREP(FLEXCAN_CBT_EPRESDIV_MASK, 0x3ff) |
> > + FIELD_PREP(FLEXCAN_CBT_ERJW_MASK, 0x1f) |
> > + FIELD_PREP(FLEXCAN_CBT_EPROPSEG_MASK, 0x3f) |
> > + FIELD_PREP(FLEXCAN_CBT_EPSEG1_MASK, 0x1f) |
> > + FIELD_PREP(FLEXCAN_CBT_EPSEG2_MASK, 0x1f));
> > +
>
> Why is this needed? The "reg_cbt &=" sets reg_cbt basically to 0, as the fields
> and the BTF occupy all 32bit.
>
> The only thing that's left over is the read()....
Yes, need not, I have not noticed it has occupy the whole 32bit.
There is a small improve patch to balance the usage_count if register flexcandev failed. Could you pick up it by the way this time?
https://www.spinics.net/lists/linux-can/msg03052.html
Best Regards,
Joakim Zhang
next prev parent reply other threads:[~2020-09-16 2:26 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-16 9:31 [PATCH Resend linux-can-next/testing] can: flexcan: add correctable errors correction when HW supports ECC Joakim Zhang
2020-04-16 9:31 ` [PATCH linux-can-next/flexcan] can: flexcan: fix TDC feature Joakim Zhang
2020-04-16 9:41 ` Joakim Zhang
2020-06-02 10:15 ` Michael Walle
2020-06-25 12:37 ` Michael Walle
2020-06-25 12:56 ` Marc Kleine-Budde
2020-06-29 5:37 ` Joakim Zhang
2020-06-29 16:23 ` Michael Walle
2020-06-30 2:25 ` Joakim Zhang
2020-09-15 22:16 ` Marc Kleine-Budde
2020-09-16 2:26 ` Joakim Zhang [this message]
2020-09-15 22:15 ` Marc Kleine-Budde
2020-07-23 21:09 ` Michael Walle
2020-09-14 15:16 ` Michael Walle
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