From: b32955@freescale.com (Huang Shijie)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 06/10] MXS-DMA : add more flags for MXS-DMA
Date: Thu, 19 Jan 2012 17:31:19 +0800 [thread overview]
Message-ID: <4F17E2E7.2080300@freescale.com> (raw)
In-Reply-To: <20120119090238.GU1068@n2100.arm.linux.org.uk>
hi,
> Err, the 'flags' argument to device_prep_slave_sg() is supposed to be
> from the set of enum dma_ctrl_flags. What this means is that your
> MXS_DMA_F_APPEND is equivalent to DMA_PREP_INTERRUPT, and
> MXS_DMA_F_WAIT4END is equivalent to DMA_CTRL_ACK.
>
thanks a lot.
I will reuse the dma_ctrl_flags in the next version.
> What this does is make your drivers completely dependent on your DMA
> engine implementation. That's not a good idea when devices get
> reused in different SoCs.
>
Frankly speaking, the APBH-DMA is more coupled with the GPMI then any
other modules.
In the MX6Q, the GPMI is the ONLY user of APBH-DMA.
You even can see the NAND_LOCK bit in the DMA command structure which is
only used by the GPMI
NAND controller,.
To Shawn & Wolfram:
thanks very much for your comments.
Best Regards
Huang Shijie
> If you need to supply extra flags which aren't in the dma_ctrl_flags,
> at least make sure that they're using different bits. For bonus points,
> also have your driver_check_ the DMA engine it's connected to before
> it passes these flags.
>
next prev parent reply other threads:[~2012-01-19 9:31 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-19 6:15 [PATCH 00/10] patch set about the MXS-DMA Huang Shijie
2012-01-19 6:15 ` [PATCH 01/10] MXS-DMA : move the mxs-dma.h to a more common place Huang Shijie
2012-01-19 8:58 ` Wolfram Sang
2012-01-19 11:20 ` Mark Brown
2012-01-19 13:04 ` Shawn Guo
2012-01-19 6:15 ` [PATCH 02/10] MXS-DMA : change the header Huang Shijie
2012-01-19 6:16 ` [PATCH 03/10] MXS-MMC : change the DMA header file Huang Shijie
2012-01-19 6:16 ` [PATCH 04/10] MTD/GPMI " Huang Shijie
2012-01-19 6:16 ` [PATCH 05/10] ASoc " Huang Shijie
2012-01-19 6:16 ` [PATCH 06/10] MXS-DMA : add more flags for MXS-DMA Huang Shijie
2012-01-19 9:02 ` Russell King - ARM Linux
2012-01-19 9:31 ` Huang Shijie [this message]
2012-01-19 6:16 ` [PATCH 07/10] MXS-DMA : change the last parameter of mxs_dma_prep_slave_sg() Huang Shijie
2012-01-19 6:16 ` [PATCH 08/10] MXS-MMC : use the new DMA flags Huang Shijie
2012-01-19 6:16 ` [PATCH 09/10] MTD/GPMI : add a new field `gpmi_version` Huang Shijie
2012-01-19 6:16 ` [PATCH 10/10] MTD/GPMI : change the code for new DMA interface Huang Shijie
2012-01-19 9:10 ` [PATCH 00/10] patch set about the MXS-DMA Shawn Guo
2012-01-19 9:45 ` Wolfram Sang
2012-01-20 3:29 ` Huang Shijie
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