Re: [PATCH] ASoC: mediatek: Enable 33bit memory address to support 4GB DRAM

From: Takashi Iwai
Date: Tue Jan 12 2016 - 00:42:48 EST


On Tue, 12 Jan 2016 03:54:44 +0100,
PC Liao wrote:
>
> On Mon, 2016-01-11 at 17:02 +0800, Takashi Iwai wrote:
> > On Mon, 11 Jan 2016 09:00:50 +0100,
> > PC Liao wrote:
> > >
> > > @@ -603,7 +606,10 @@ static int mtk_afe_dais_hw_params(struct snd_pcm_substream *substream,
> > > if (ret < 0)
> > > return ret;
> > >
> > > - memif->phys_buf_addr = substream->runtime->dma_addr;
> > > + if (sizeof(dma_addr_t) > 4)
> > > + msb_at_bit33 = (substream->runtime->dma_addr & 0x100000000) ? 1 : 0;
> >
> > Better to put a proper suffix for the constant over 32bit.
> >
> > Or use upper_32_bits(). Then sizeof() check can be omitted, as the
> > compiler should be smart enough to know it beforehand.
> >
> >
> > Takashi
>
>
> Hi Takashi,
>
> Thanks for your comment.
> I change as below:
> @@ -606,10 +606,8 @@ static int mtk_afe_dais_hw_params(struct
> snd_pcm_substream
> if (ret < 0)
> return ret;
>
> - if (sizeof(dma_addr_t) > 4)
> - msb_at_bit33 = (substream->runtime->dma_addr &
> 0x100000000) ? 1
> -
> - memif->phys_buf_addr = substream->runtime->dma_addr &
> 0xffffffff;
> + msb_at_bit33 = upper_32_bits(substream->runtime->dma_addr) ? 1 :
> 0;
> + memif->phys_buf_addr =
> lower_32_bits(substream->runtime->dma_addr);
>
>
> Dose this change follow your idea?

Yes.


Takashi