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Commit 20698c92 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'dmaengine-fix-4.5' of git://git.infradead.org/users/vkoul/slave-dma 

Pull dmaengine fixes from Vinod Koul:
 "Two fixes showed up in last few days, and they should be included in
  4.5.  Summary:

  Two more late fixes to drivers, nothing major here:

   - A memory leak fix in fsdma unmap the dma descriptors on freeup

   - A fix in xdmac driver for residue calculation of dma descriptor"

* tag 'dmaengine-fix-4.5' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: at_xdmac: fix residue computation
  dmaengine: fsldma: fix memory leak
parents 7ae9c768 25c5e962

drivers/dma/at_xdmac.c

+39 −3
Original line number Diff line number Diff line
@@ -176,6 +176,7 @@ 
#define AT_XDMAC_MAX_CHAN	0x20

#define AT_XDMAC_MAX_CSIZE	16	/* 16 data */

#define AT_XDMAC_MAX_DWIDTH	8	/* 64 bits */

#define AT_XDMAC_RESIDUE_MAX_RETRIES	5



#define AT_XDMAC_DMA_BUSWIDTHS\

	(BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) |\
@@ -1395,8 +1396,8 @@ at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie, 
	struct at_xdmac_desc	*desc, *_desc;

	struct list_head	*descs_list;

	enum dma_status		ret;

	int			residue;

	u32			cur_nda, mask, value;

	int			residue, retry;

	u32			cur_nda, check_nda, cur_ubc, mask, value;

	u8			dwidth = 0;

	unsigned long		flags;
@@ -1433,7 +1434,42 @@ at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie, 
			cpu_relax();

	}



	/*

	 * When processing the residue, we need to read two registers but we

	 * can't do it in an atomic way. AT_XDMAC_CNDA is used to find where

	 * we stand in the descriptor list and AT_XDMAC_CUBC is used

	 * to know how many data are remaining for the current descriptor.

	 * Since the dma channel is not paused to not loose data, between the

	 * AT_XDMAC_CNDA and AT_XDMAC_CUBC read, we may have change of

	 * descriptor.

	 * For that reason, after reading AT_XDMAC_CUBC, we check if we are

	 * still using the same descriptor by reading a second time

	 * AT_XDMAC_CNDA. If AT_XDMAC_CNDA has changed, it means we have to

	 * read again AT_XDMAC_CUBC.

	 * Memory barriers are used to ensure the read order of the registers.

	 * A max number of retries is set because unlikely it can never ends if

	 * we are transferring a lot of data with small buffers.

	 */

	cur_nda = at_xdmac_chan_read(atchan, AT_XDMAC_CNDA) & 0xfffffffc;

	rmb();

	cur_ubc = at_xdmac_chan_read(atchan, AT_XDMAC_CUBC);

	for (retry = 0; retry < AT_XDMAC_RESIDUE_MAX_RETRIES; retry++) {

		rmb();

		check_nda = at_xdmac_chan_read(atchan, AT_XDMAC_CNDA) & 0xfffffffc;



		if (likely(cur_nda == check_nda))

			break;



		cur_nda = check_nda;

		rmb();

		cur_ubc = at_xdmac_chan_read(atchan, AT_XDMAC_CUBC);

	}



	if (unlikely(retry >= AT_XDMAC_RESIDUE_MAX_RETRIES)) {

		ret = DMA_ERROR;

		goto spin_unlock;

	}



	/*

	 * Remove size of all microblocks already transferred and the current

	 * one. Then add the remaining size to transfer of the current
@@ -1446,7 +1482,7 @@ at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie, 
		if ((desc->lld.mbr_nda & 0xfffffffc) == cur_nda)

			break;

	}

	residue += at_xdmac_chan_read(atchan, AT_XDMAC_CUBC) << dwidth;

	residue += cur_ubc << dwidth;



	dma_set_residue(txstate, residue);

drivers/dma/fsldma.c

+2 −0
Original line number Diff line number Diff line
@@ -522,6 +522,8 @@ static dma_cookie_t fsldma_run_tx_complete_actions(struct fsldma_chan *chan, 
			chan_dbg(chan, "LD %p callback\n", desc);

			txd->callback(txd->callback_param);

		}



		dma_descriptor_unmap(txd);

	}



	/* Run any dependencies */