From: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>
To: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>,
lukas@mntmn.com, linux-kernel@vger.kernel.org,
dri-devel@lists.freedesktop.org,
NXP Linux Team <linux-imx@nxp.com>,
Pengutronix Kernel Team <kernel@pengutronix.de>,
Laurentiu Palcu <laurentiu.palcu@nxp.com>,
Shawn Guo <shawnguo@kernel.org>,
agx@sigxcpu.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3 2/4] drm/imx: Add initial support for DCSS on iMX8MQ
Date: Fri, 6 Mar 2020 13:12:10 +0200 [thread overview]
Message-ID: <20200306111210.q7fceoahqw3mlxog@fsr-ub1864-141> (raw)
In-Reply-To: <69903c69a95902c0ddc8fb9e7a6762abf28aa034.camel@pengutronix.de>
Hi Philipp,
On Fri, Mar 06, 2020 at 11:20:51AM +0100, Philipp Zabel wrote:
> Hi Laurentiu,
>
> On Fri, 2020-03-06 at 11:58 +0200, Laurentiu Palcu wrote:
> > On Wed, Feb 26, 2020 at 02:19:11PM +0100, Lucas Stach wrote:
> [...]
> > > > +/* This function will be called from interrupt context. */
> > > > +void dcss_scaler_write_sclctrl(struct dcss_scaler *scl)
> > > > +{
> > > > + int chnum;
> > > > +
> > > > + for (chnum = 0; chnum < 3; chnum++) {
> > > > + struct dcss_scaler_ch *ch = &scl->ch[chnum];
> > > > +
> > > > + if (ch->scaler_ctrl_chgd) {
> > > > + dcss_ctxld_write_irqsafe(scl->ctxld, scl->ctx_id,
> > > > + ch->scaler_ctrl,
> > > > + ch->base_ofs +
> > > > + DCSS_SCALER_CTRL);
> > >
> > > Why is this using the _irqsafe variant without any locking? Won't this
> > > lead to potential internal state corruption? dcss_ctxld_write is using
> > > the _irqsave locking variants, so it fine with being called from IRQ
> > > context.
> >
> > This is only called from __dcss_ctxld_enable() which is already protected
> > by lock/unlock in dcss_ctxld_kick().
>
> You could add a lockdep_assert_held() line to the top of this function
> to make it clear this depends on the lock being held.
Thanks for the suggestion. Will add a check.
Thanks,
laurentiu
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next prev parent reply other threads:[~2020-03-06 11:12 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-06 9:52 [PATCH v3 0/4] Add support for iMX8MQ Display Controller Subsystem Laurentiu Palcu
2019-12-06 9:52 ` [PATCH v3 1/4] drm/imx: compile imx directory by default Laurentiu Palcu
2019-12-06 9:52 ` [PATCH v3 2/4] drm/imx: Add initial support for DCSS on iMX8MQ Laurentiu Palcu
2020-02-24 17:27 ` Lucas Stach
2020-02-26 7:52 ` Laurentiu Palcu
2020-02-26 13:19 ` Lucas Stach
2020-03-06 9:58 ` Laurentiu Palcu
2020-03-06 10:20 ` Philipp Zabel
2020-03-06 11:12 ` Laurentiu Palcu [this message]
2019-12-06 9:52 ` [PATCH v3 3/4] dt-bindings: display: imx: add bindings for DCSS Laurentiu Palcu
2020-02-24 17:21 ` Lucas Stach
2020-02-26 7:58 ` Laurentiu Palcu
2020-02-27 11:52 ` Philipp Zabel
2019-12-11 20:16 ` [PATCH v3 0/4] Add support for iMX8MQ Display Controller Subsystem Lukas Hartmann
2020-02-21 12:15 ` Guido Günther
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