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

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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
This commit is contained in:
Linus Torvalds
2016-03-11 10:57:18 -08:00
parent 7ae9c768e1 25c5e9626c
commit 20698c922f
2 changed files with 41 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

42
drivers/dma/at_xdmac.c
View File

@@ -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);

2
drivers/dma/fsldma.c
View File

@@ -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 */