linux-kernel - Re: [PATCH] media: stm32-dcmi: Use dma_request_chan() instead dma_request_slave

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <2434a772-f8b2-a954-e370-2d8dff60ade2@st.com>
Date:   Tue, 7 Jan 2020 11:08:17 +0000
From:   Hugues FRUCHET <hugues.fruchet@...com>
To:     Peter Ujfalusi <peter.ujfalusi@...com>,
        "mchehab@...nel.org" <mchehab@...nel.org>,
        "mcoquelin.stm32@...il.com" <mcoquelin.stm32@...il.com>,
        Alexandre TORGUE <alexandre.torgue@...com>
CC:     "vkoul@...nel.org" <vkoul@...nel.org>,
        "linux-media@...r.kernel.org" <linux-media@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-stm32@...md-mailman.stormreply.com" 
        <linux-stm32@...md-mailman.stormreply.com>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH] media: stm32-dcmi: Use dma_request_chan() instead
 dma_request_slave_channel()

Y're welcome.

On 1/7/20 11:38 AM, Peter Ujfalusi wrote:
> Hi Hugues,
> 
> On 07/01/2020 11.46, Hugues FRUCHET wrote:
>> Hi Peter,
>>
>> If not too late, could you change trace to only trig error trace when
>> error is not "probe defered" ? See below:
>>
>> -	chan = dma_request_slave_channel(&pdev->dev, "tx");
>> -	if (!chan) {
>> -		dev_info(&pdev->dev, "Unable to request DMA channel, defer probing\n");
>> -		return -EPROBE_DEFER;
>> +	chan = dma_request_chan(&pdev->dev, "tx");
>> +	if (IS_ERR(chan)) {
>> +		if (PTR_ERR(chan) != -EPROBE_DEFER)
>> +			dev_err(&pdev->dev, "Unable to request DMA channel\n");
>> +		return PTR_ERR(chan);
> 
> Sure, I don't know how I missed it.
> 
> Regards,
> - Péter
> 
>>
>> Best regards,
>> Hugues.
>>
>> On 12/18/19 11:52 AM, Hugues FRUCHET wrote:
>>> Thanks for patching Peter,
>>>
>>> No regression observed on my side.
>>>
>>> Acked-by: Hugues Fruchet <hugues.fruchet@...com>
>>>
>>> Best regards,
>>> Hugues.
>>>
>>> On 12/17/19 11:41 AM, Peter Ujfalusi wrote:
>>>> dma_request_slave_channel() is a wrapper on top of dma_request_chan()
>>>> eating up the error code.
>>>>
>>>> By using dma_request_chan() directly the driver can support deferred
>>>> probing against DMA.
>>>>
>>>> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@...com>
>>>> ---
>>>>    drivers/media/platform/stm32/stm32-dcmi.c | 6 +++---
>>>>    1 file changed, 3 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/drivers/media/platform/stm32/stm32-dcmi.c
>>>> b/drivers/media/platform/stm32/stm32-dcmi.c
>>>> index 9392e3409fba..55351872b0c7 100644
>>>> --- a/drivers/media/platform/stm32/stm32-dcmi.c
>>>> +++ b/drivers/media/platform/stm32/stm32-dcmi.c
>>>> @@ -1910,10 +1910,10 @@ static int dcmi_probe(struct platform_device
>>>> *pdev)
>>>>            return PTR_ERR(mclk);
>>>>        }
>>>> -    chan = dma_request_slave_channel(&pdev->dev, "tx");
>>>> -    if (!chan) {
>>>> +    chan = dma_request_chan(&pdev->dev, "tx");
>>>> +    if (IS_ERR(chan)) {
>>>>            dev_info(&pdev->dev, "Unable to request DMA channel, defer
>>>> probing\n");
>>>> -        return -EPROBE_DEFER;
>>>> +        return PTR_ERR(chan);
>>>>        }
>>>>        spin_lock_init(&dcmi->irqlock);
>>>>
> 
> 
> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
>