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[PATCH v2 02/15] dmaengine: dw: clear LLP_[SD]_EN bits in last descriptor of a chain

From Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Newsgroups linux.kernel
Subject [PATCH v2 02/15] dmaengine: dw: clear LLP_[SD]_EN bits in last descriptor of a chain
Date 2016-02-22 17:10 +0100
Message-ID <r51dF-8d4-37@gated-at.bofh.it> (permalink)
References <r51dD-8d4-1@gated-at.bofh.it>
Organization linux.* mail to news gateway

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From: Mans Rullgard <mans@mansr.com>

The datasheet requires that the LLP_[SD]_EN bits be cleared whenever
LLP.LOC is zero, i.e. in the last descriptor of a multi-block chain.
Make the driver do this.

Signed-off-by: Mans Rullgard <mans@mansr.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/dma/dw/core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index cd7616e..4a823f4 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -763,6 +763,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 		lli_set(prev, ctllo, DWC_CTLL_INT_EN);
 
 	prev->lli.llp = 0;
+	lli_clear(prev, ctllo, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
 	first->txd.flags = flags;
 	first->total_len = len;
 
@@ -922,6 +923,7 @@ slave_sg_fromdev_fill_desc:
 		lli_set(prev, ctllo, DWC_CTLL_INT_EN);
 
 	prev->lli.llp = 0;
+	lli_clear(prev, ctllo, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
 	first->total_len = total_len;
 
 	return &first->txd;
-- 
2.7.0

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Thread

[PATCH v2 00/15] Fixes / cleanups in dw_dmac (affects on few subsystems) Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-02-22 17:10 +0100
  [PATCH v2 10/15] dmaengine: dw: pass platform data via struct dw_dma_chip Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-02-22 17:10 +0100
  [PATCH v2 14/15] dmaengine: dw: move residue to a descriptor Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-02-22 17:10 +0100
  [PATCH v2 07/15] dmaengine: dw: revisit data_width property Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-02-22 17:10 +0100
  [PATCH v2 09/15] dmaengine: dw: keep entire platform data in struct dw_dma Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-02-22 17:10 +0100
  [PATCH v2 01/15] dmaengine: dw: fix byte order of hw descriptor fields Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-02-22 17:10 +0100
  [PATCH v2 11/15] dmaengine: dw: platform: use field-by-field initialization Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-02-22 17:10 +0100
  [PATCH v2 08/15] dmaengine: dw: define counter variables as unsigned int Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-02-22 17:10 +0100
  [PATCH v2 15/15] dmaengine: dw: set cdesc to NULL when free cyclic transfers Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-02-22 17:10 +0100
  [PATCH v2 02/15] dmaengine: dw: clear LLP_[SD]_EN bits in last descriptor of a chain Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-02-22 17:10 +0100
  [PATCH v2 13/15] dmaengine: dw: move dwc->initialized to dwc->flags Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-02-22 17:10 +0100
  [PATCH v2 04/15] dmaengine: dw: set src and dst master select according to xfer direction Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-02-22 17:10 +0100
  [PATCH v2 12/15] dmaengine: dw: move dwc->paused to dwc->flags Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-02-22 17:10 +0100
  [PATCH v2 03/15] dmaengine: dw: rename masters to reflect actual topology Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-02-22 17:10 +0100
  [PATCH v2 06/15] dmaengine: dw: substitute dma_read_byaddr by dma_readl_native Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-02-22 17:10 +0100
  [PATCH v2 05/15] dmaengine: dw: set LMS field in descriptors Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-02-22 17:10 +0100

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