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

["Agrawal, Akshu" <Akshu.Agrawal@amd.com>]

On 11/21/2017 10:17 AM, Deucher, Alexander wrote:
>> -----Original Message-----
>> From: Guenter Roeck [mailto:groeck7@gmail.com] 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@alsa-project.org;
>> linux-kernel@vger.kernel.org; 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@amd.com>
>> Cc: Dominik Behr <dbehr@chromium.org>
>> Cc: Daniel Kurtz <djkurtz@chromium.org>
>> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
>> ---
>> 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@amd.com>
> 
>>
>>   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
>