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From: Lee Jones <lee.jones@linaro.org>
To: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Cc: Luo Meng <luomeng12@huawei.com>, Roger Quadros <rogerq@ti.com>,
	linux-arm-kernel@lists.infradead.org,
	Santosh Shilimkar <ssantosh@kernel.org>
Subject: Re: [PATCH] soc: ti: pruss: fix return check for of_device_get_match_data()
Date: Tue, 10 Nov 2020 09:54:18 +0000	[thread overview]
Message-ID: <20201110095418.GH2063125@dell> (raw)
In-Reply-To: <CAMxfBF4Q7gkC76SHLyqjFKGUODx_-BT61C2gb1KzPLeCbNx=qg@mail.gmail.com>

On Tue, 10 Nov 2020, Grzegorz Jaszczyk wrote:

> Hi
> 
> On Tue, 10 Nov 2020 at 02:31, Luo Meng <luomeng12@huawei.com> wrote:
> >
> > of_device_get_match_data() maybe return NULL pointer which cannot
> > be checked with IS_ERR.
> >
> > Fixes: ba59c9b43c86 ("soc: ti: pruss: support CORECLK_MUX and IEPCLK_MUX")
> > Reported-by: Hulk Robot <hulkci@huawei.com>
> > Signed-off-by: Luo Meng <luomeng12@huawei.com>
> > ---
> >  drivers/soc/ti/pruss.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/soc/ti/pruss.c b/drivers/soc/ti/pruss.c
> > index cc0b4ad7a3d3..582f48051c30 100644
> > --- a/drivers/soc/ti/pruss.c
> > +++ b/drivers/soc/ti/pruss.c
> > @@ -126,7 +126,7 @@ static int pruss_clk_init(struct pruss *pruss, struct device_node *cfg_node)
> >         int ret = 0;
> >
> >         data = of_device_get_match_data(dev);
> > -       if (IS_ERR(data))
> > +       if (!data)
> >                 return -ENODEV;

Also this would miss any errors, leading to dereference issues.

I think what you meant was IS_ERR_OR_NULL(), but this would still be
incorrect for the reasons Grzegorz mentions below.

> >         clks_np = of_get_child_by_name(cfg_node, "clocks");
> > @@ -175,7 +175,7 @@ static int pruss_probe(struct platform_device *pdev)
> >         const char *mem_names[PRUSS_MEM_MAX] = { "dram0", "dram1", "shrdram2" };
> >
> >         data = of_device_get_match_data(&pdev->dev);
> > -       if (IS_ERR(data)) {
> > +       if (!data) {
> 
> Thank you for your interest but with your patch the driver will not be
> functional anymore for all devices without match data (e.g.
> "ti,am3356-pruss") which is not what we want. The proper fix was
> already posted end of October:
> https://patchwork.kernel.org/project/linux-arm-kernel/patch/20201026144943.30821-1-grzegorz.jaszczyk@linaro.org/
> 
> Thank you,
> Grzegorz

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog

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  reply	other threads:[~2020-11-10  9:54 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-10  1:33 [PATCH] soc: ti: pruss: fix return check for of_device_get_match_data() Luo Meng
2020-11-10  8:28 ` Grzegorz Jaszczyk
2020-11-10  9:54   ` Lee Jones [this message]
2020-11-10 20:41     ` Suman Anna

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