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| author | Gregory Nutt <gnutt@nuttx.org> | 2013-12-07 07:00:48 -0600 |
|---|---|---|
| committer | Gregory Nutt <gnutt@nuttx.org> | 2013-12-07 07:00:48 -0600 |
| commit | 7b997e614e6be347eadde1f39ef390dcf5a262e0 (patch) | |
| tree | 34954ef442b71dadd3511c0fe56a5846f5d13c38 | |
| parent | 0f40dc1be811c553ef38bdf3cde239489eb174d5 (diff) | |
| download | px4-nuttx-7b997e614e6be347eadde1f39ef390dcf5a262e0.tar.gz px4-nuttx-7b997e614e6be347eadde1f39ef390dcf5a262e0.tar.bz2 px4-nuttx-7b997e614e6be347eadde1f39ef390dcf5a262e0.zip | |
Minor updates to comments and README files
| -rw-r--r-- | nuttx/arch/arm/src/sama5/sam_dmac.c | 6 | ||||
| -rw-r--r-- | nuttx/configs/sama5d3x-ek/README.txt | 13 |
2 files changed, 10 insertions, 9 deletions
diff --git a/nuttx/arch/arm/src/sama5/sam_dmac.c b/nuttx/arch/arm/src/sama5/sam_dmac.c index da58c2971..f332db715 100644 --- a/nuttx/arch/arm/src/sama5/sam_dmac.c +++ b/nuttx/arch/arm/src/sama5/sam_dmac.c @@ -1487,11 +1487,13 @@ static void sam_freelinklist(struct sam_dmach_s *dmach) DEBUGASSERT(desc->saddr != 0); - /* Get the physical address of the next desriptor in the list */ + /* Get the physical address of the next descriptor in the list */ paddr = desc->dscr; - /* Free the descriptor by simply nullifying it */ + /* Free the descriptor by simply nullifying it and bumping up the + * semaphore count. + */ memset(desc, 0, sizeof(struct dma_linklist_s)); sam_givedsem(dmac); diff --git a/nuttx/configs/sama5d3x-ek/README.txt b/nuttx/configs/sama5d3x-ek/README.txt index 4c14af7d3..390fb1b5b 100644 --- a/nuttx/configs/sama5d3x-ek/README.txt +++ b/nuttx/configs/sama5d3x-ek/README.txt @@ -1358,9 +1358,9 @@ NAND Support verified, but there is no way to use it in the current NuttX architecture other than through the raw MTD interface. - NAND should be considered a work in progress. You will not want to use - NAND unless you are interested in investing a little effort, particularly - in infrastructure. See the "STATUS SUMMARY" section below. + NAND should still be considered a work in progress. You will not want to + use NAND unless you are interested in investing a little effort, + particularly in infrastructure. See the "STATUS SUMMARY" section below. NAND Support ------------ @@ -1652,13 +1652,12 @@ NAND Support work correctly: The MBR is written and read back correctly, but gets corrupted later for unknown reasons. - 2. DMA works (with software ECC), but I have seen occasional failurs. I - believe that these issue have been resolved but I recommend enabling - DMA with caution. + 2. DMA works (at least with software ECC), but I have seen occasional + failures. I recommend enabling DMA with caution. In NuttX, DMA will also cost two context switches (and, hence, four register state transfers). With smaller NAND page sizes (say 2KiB and - below), I would not expect a great performance improvement with DMA + below), I would expect little or no performance improvement with DMA for this reason. 3. NXFFS does not work with NAND. NAND differs from other other FLASH |