From: Ahmad Fatoum <a.fatoum@pengutronix.de> To: Bastian Krause <bst@pengutronix.de>, barebox@lists.infradead.org Subject: Re: [PATCH v2] clk: handle NULL args in clk_{g,s}et_parent() Date: Wed, 11 May 2022 14:46:19 +0200 [thread overview] Message-ID: <45cf07ce-bd1b-ef48-52f0-820642e0635a@pengutronix.de> (raw) In-Reply-To: <20220511123139.2767034-1-bst@pengutronix.de> On 11.05.22 14:31, Bastian Krause wrote: > NULL struct clk pointers should be treated just as the Linux kernel clk > driver does [1]. The reasoning should also apply to the parent clk > argument. > > A NULL struct clk pointer can happen for example on the Freescale i.MX6 > SABRE Smart Device Board if CONFIG_DRIVER_VIDEO_IMX_IPUV3 is disabled, > leading to assigned-clocks IMX6QDL_CLK_LDB_DI0_SEL and > IMX6QDL_CLK_LDB_DI1_SEL [2] being unavailable. Without this patch, the > board hangs while setting those assigned clock configurations since [3]. > > [1] 89ac8d7ae1cd ("clk: handle NULL struct clk gracefully") > [2] dts/src/arm/imx6qdl-sabresd.dtsi > [3] f5eb5fddb4 ("clk: fix of clk set defaults when dev is a clk provider") > > Signed-off-by: Bastian Krause <bst@pengutronix.de> Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de> > --- > Changes since (implicit) v1: > - make clk_get_parent(NULL) return NULL > - undo shifting call to clk_get_parent() in clk_set_parent() > --- > drivers/clk/clk.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > index 8e317b4b05..52e309e877 100644 > --- a/drivers/clk/clk.c > +++ b/drivers/clk/clk.c > @@ -232,6 +232,9 @@ int clk_set_parent(struct clk *clk, struct clk *newparent) > int i, ret; > struct clk *curparent = clk_get_parent(clk); > > + if (!clk || !newparent) > + return 0; > + > if (IS_ERR(clk)) > return PTR_ERR(clk); > if (IS_ERR(newparent)) > @@ -287,7 +290,7 @@ struct clk *clk_get_parent(struct clk *clk) > struct clk_hw *hw; > int idx; > > - if (IS_ERR(clk)) > + if (IS_ERR_OR_NULL(clk)) > return clk; > > if (!clk->num_parents) -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox
prev parent reply other threads:[~2022-05-11 12:47 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-05-11 12:31 Bastian Krause 2022-05-11 12:46 ` Ahmad Fatoum [this message]
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