From: Marek Vasut <marex@denx.de>
To: Huang Shijie <b32955@freescale.com>
Subject: Re: [PATCH] dma: add new DMA control commands
Date: Thu, 18 Oct 2012 12:51:14 +0200
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Cc: Vinod Koul <vinod.koul@linux.intel.com>, djbw@fb.com, khali@linux-fr.org,
        ben-linux@fluff.org, w.sang@pengutronix.de, cjb@laptop.org,
        dwmw2@infradead.org, lrg@ti.com, broonie@opensource.wolfsonmicro.com,
        perex@perex.cz, tiwai@suse.de, shawn.guo@linaro.org,
        artem.bityutskiy@linux.intel.com, linux-kernel@vger.kernel.org,
        linux-i2c@vger.kernel.org, linux-mmc@vger.kernel.org,
        linux-mtd@lists.infradead.org, alsa-devel@alsa-project.org,
        linux-arm-kernel@lists.infradead.org, linux@arm.linux.org.uk,
        Huang Shijie <shijie8@gmail.com>,
        Fabio Estevam <fabio.estevam@freescale.com>
References: <1350538335-29026-1-git-send-email-b32955@freescale.com> <201210181049.21556.marex@denx.de> <507FC827.40601@freescale.com>
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Dear Huang Shijie,

> 于 2012年10月18日 16:49, Marek Vasut 写道:
> > Dear Huang Shijie,
> > 
> >> 于 2012年10月18日 16:16, Marek Vasut 写道:
> >>> So we can't stream data from the chip? About time to adjust the MTD
> >>> framework to allow that. Maybe implement a command queue?
> >> 
> >> IMHO, it's not possible. Because the READ-PAGE(00h-30h) command needs to
> >> check the busy status
> >> which means we have to stop in the middle, so we can not chain the all
> >> the read-pages DMA commands.
> > 
> > Can the DMA not branch?
> 
> it's too complicated to the MTD layer, as well as the gpmi driver.

Can you please elaborate ?

Best regards,
Marek Vasut
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