diff options
| author | Robin Gong <yibin.gong@nxp.com> | 2018-06-20 00:57:00 +0800 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2018-07-02 18:24:47 +0530 |
| commit | 57b772b86871e025c1fc149d8c3e48667be0869f (patch) | |
| tree | 644f5c0380f8f1d3a53f0f90a0fb7fb5c5d2bf79 /drivers/dma/Kconfig | |
| parent | 76c33d27073e29bd98d1c975265e1cbe0889fc53 (diff) | |
dmaengine: imx-sdma: add virt-dma support
The legacy sdma driver has below limitations or drawbacks:
1. Hardcode the max BDs number as "PAGE_SIZE / sizeof(*)", and alloc
one page size for one channel regardless of only few BDs needed
most time. But in few cases, the max PAGE_SIZE maybe not enough.
2. One SDMA channel can't stop immediatley once channel disabled which
means SDMA interrupt may come in after this channel terminated.There
are some patches for this corner case such as commit "2746e2c389f9",
but not cover non-cyclic.
The common virt-dma overcomes the above limitations. It can alloc bd
dynamically and free bd once this tx transfer done. No memory wasted or
maximum limititation here, only depends on how many memory can be requested
from kernel. For No.2, such issue can be workaround by checking if there
is available descript("sdmac->desc") now once the unwanted interrupt
coming. At last the common virt-dma is easier for sdma driver maintain.
Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Tested-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma/Kconfig')
| -rw-r--r-- | drivers/dma/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index ca1680afa20a..d4a4230a7942 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -250,6 +250,7 @@ config IMX_SDMA tristate "i.MX SDMA support" depends on ARCH_MXC select DMA_ENGINE + select DMA_VIRTUAL_CHANNELS help Support the i.MX SDMA engine. This engine is integrated into Freescale i.MX25/31/35/51/53/6 chips. |