Re: [PATCH v3 2/2] DW DMAC: add multi-block property to device tree
From: Andy Shevchenko <hidden>
Date: 2016-11-18 19:33:20
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On Fri, 2016-11-18 at 22:12 +0300, Eugeniy Paltsev wrote:
Several versions of DW DMAC have multi block transfers hardware support. Hardware support of multi block transfers is disabled by default if we use DT to configure DMAC and software emulation of multi block transfers used instead. Add multi-block property, so it is possible to enable hardware multi block transfers (if present) via DT. Switch from per device is_nollp variable to multi_block array to be able enable/disable multi block transfers separately per channel.
Update DT documentation. Update existing platform data.
Kinda useless for commit message, but might go after --- delimiter.
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev-HKixBCOQz3hWk0Htik3J/w@public.gmane.org> --- Documentation/devicetree/bindings/dma/snps-dma.txt | 2 ++ drivers/dma/dw/core.c | 2 +- drivers/dma/dw/platform.c | 5 +++++ drivers/tty/serial/8250/8250_lpss.c | 2 +- include/linux/platform_data/dma-dw.h | 4 ++-- 5 files changed, 11 insertions(+), 4 deletions(-)
quoted hunk ↗ jump to hunk
--- a/Documentation/devicetree/bindings/dma/snps-dma.txt +++ b/Documentation/devicetree/bindings/dma/snps-dma.txt@@ -27,6 +27,8 @@ Optional properties:that services interrupts for this device - is_private: The device channels should be marked as private and not for by the general purpose DMA channel allocator. False if not passed. +- multi-block: Multi block transfers supported by hardware per AHB master. + 0 (default): not supported, 1: supported. Example:diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c index c2c0a61..f2a3d06 100644 --- a/drivers/dma/dw/core.c +++ b/drivers/dma/dw/core.c@@ -1569,7 +1569,7 @@ int dw_dma_probe(struct dw_dma_chip *chip)(dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0; } else { dwc->block_size = pdata->block_size; - dwc->nollp = pdata->is_nollp; + dwc->nollp = pdata->multi_block[i];
You missed the point. You assign positive value to negative variable. It's a bug. Have you tested this? How? In case of positive property you have to update DTS. By the way, I'm pretty sure that spare13xx boards has auto configuration enabled, though it has to be checked with vendor (I assume you may have fast response from them).
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-- Andy Shevchenko [off-list ref] Intel Finland Oy -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html