From mboxrd@z Thu Jan  1 00:00:00 1970
From: nikita.yoush@cogentembedded.com (Nikita Yushchenko)
Date: Mon, 9 Jan 2017 09:56:34 +0300
Subject: [PATCH] arm64: do not set dma masks that device connection can't
 handle
In-Reply-To: <d60c54cd-ca62-4c56-7545-17e15f80b797@cogentembedded.com>
References: <9a03c05d-ad4c-0547-d1fe-01edb8b082d6@cogentembedded.com>
 <1483713911-2079-1-git-send-email-nikita.yoush@cogentembedded.com>
 <d60c54cd-ca62-4c56-7545-17e15f80b797@cogentembedded.com>
Message-ID: <5c4736a6-4d0b-342e-2a5c-9aaaa933b138@cogentembedded.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

>> +    if (mask > dev->archdata.parent_dma_mask)
>> +        mask = dev->archdata.parent_dma_mask;
>> +
>> +
> 
>    One empty line is enough...

Ok

>> +    /*
>> +     * Whatever the parent bus can set. A device must not set
>> +     * a DMA mask larger than this.
>> +     */
>> +    dev->archdata.parent_dma_mask = size;
> 
>    Not 'size - 1'?

Good question.

Indeed of_dma_configure() calls arch_setup_dma_ops() with size, not
mask. Which implies '-1' is needed here. Although better fix may be to
change caller side - to make DMA_BIT_MASK(64) case cleaner.

Will repost path.

Nikita