Re: [PATCH] ASoC: amd: Add error checking to probe function

[Agrawal, Akshu]

On 11/21/2017 10:17 AM, Deucher, Alexander wrote:
> > -----Original Message-----
> > From: Guenter Roeck [mailto:groeck7@xxxxxxxxx] On Behalf Of Guenter
> > Roeck
> > Sent: Monday, November 20, 2017 11:28 PM
> > To: Liam Girdwood
> > Cc: Mark Brown; Jaroslav Kysela; Takashi Iwai; alsa-devel@xxxxxxxxxxxxxxxx;
> > linux-kernel@xxxxxxxxxxxxxxx; Guenter Roeck; Deucher, Alexander; Dominik
> > Behr; Daniel Kurtz
> > Subject: [PATCH] ASoC: amd: Add error checking to probe function
> >
> > The acp_audio_dma does not perform sufficient error checking in its probe
> > function. This can result in crashes if a critical error path is
> > encountered.
> >
> > Fixes: 7c31335a03b6a ("ASoC: AMD: add AMD ASoC ACP 2.x DMA driver")
> > Cc: Alex Deucher <alexander.deucher@xxxxxxx>
> > Cc: Dominik Behr <dbehr@xxxxxxxxxxxx>
> > Cc: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
> > Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> > ---
> > I didn't add an error check to acp_init() since I was not sure if
> > its return value is ignored on purpose.
>
> Vijendar, Akshu can you comment?

This is also the case of missing error check.
acp_init will return error if either sw reset did not happen or clock 
did not get enabled. In both cases we should error out in probe.

> The patch looks good to me.
> Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx>
>
> >   sound/soc/amd/acp-pcm-dma.c | 7 +++++++
> >   1 file changed, 7 insertions(+)
> >
> > diff --git a/sound/soc/amd/acp-pcm-dma.c b/sound/soc/amd/acp-pcm-
> > dma.c
> > index 9f521a55d610..b5e41df6bb3a 100644
> > --- a/sound/soc/amd/acp-pcm-dma.c
> > +++ b/sound/soc/amd/acp-pcm-dma.c
> > @@ -1051,6 +1051,11 @@ static int acp_audio_probe(struct platform_device
> > *pdev)
> >   	struct resource *res;
> >   	const u32 *pdata = pdev->dev.platform_data;
> >
> > +	if (!pdata) {
> > +		dev_err(&pdev->dev, "Missing platform data\n");
> > +		return -ENODEV;
> > +	}
> > +
> >   	audio_drv_data = devm_kzalloc(&pdev->dev, sizeof(struct
> > audio_drv_data),
> >   					GFP_KERNEL);
> >   	if (audio_drv_data == NULL)
> > @@ -1058,6 +1063,8 @@ static int acp_audio_probe(struct platform_device
> > *pdev)
> >
> >   	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >   	audio_drv_data->acp_mmio = devm_ioremap_resource(&pdev-
> > > dev, res);
> > +	if (IS_ERR(audio_drv_data->acp_mmio))
> > +		return PTR_ERR(audio_drv_data->acp_mmio);
> >
> >   	/* The following members gets populated in device 'open'
> >   	 * function. Till then interrupts are disabled in 'acp_init'
> > --
> > 2.7.4