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| author | Russell King - ARM Linux <linux@arm.linux.org.uk> | 2011-01-03 22:42:55 +0000 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2011-01-04 19:16:13 -0800 |
| commit | 5f638b4f313e345bf02700910e581bccf71212f5 (patch) | |
| tree | 423d49f0935c3f2977e3aae1cb7b4d402d0c257a /drivers/dma | |
| parent | d6cf7b597f7158616106068930d1c6203d9359eb (diff) | |
| download | lwn-5f638b4f313e345bf02700910e581bccf71212f5.tar.gz lwn-5f638b4f313e345bf02700910e581bccf71212f5.zip | |
ARM: PL08x: fix fill_bytes calculation
The number of bytes we want to fill into any LLI is the minimum of:
- number of bytes remaining in the transfer
- number of bytes we can transfer in a single LLI
- number of bytes we can transfer without overflowing the source boundary
- number of bytes we can transfer without overflowing the destination boundary
The minimum of the first two is already calculated (target_len). We
limit the boundary calculations to this number of bytes, which will
then give us the number of bytes we can place into this LLI.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/amba-pl08x.c | 26 |
1 files changed, 10 insertions, 16 deletions
diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c index 91dd6bfcc30f..be7fa174d6c0 100644 --- a/drivers/dma/amba-pl08x.c +++ b/drivers/dma/amba-pl08x.c @@ -685,31 +685,25 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x, target_len = min(remainder, max_bytes_per_lli); /* - * Set bus lengths for incrementing buses - * to number of bytes which fill to next memory - * boundary + * Set bus lengths for incrementing buses to the + * number of bytes which fill to next memory boundary, + * limiting on the target length calculated above. */ if (cctl & PL080_CONTROL_SRC_INCR) txd->srcbus.fill_bytes = - pl08x_pre_boundary( - txd->srcbus.addr, - remainder); + pl08x_pre_boundary(txd->srcbus.addr, + target_len); else - txd->srcbus.fill_bytes = - max_bytes_per_lli; + txd->srcbus.fill_bytes = target_len; if (cctl & PL080_CONTROL_DST_INCR) txd->dstbus.fill_bytes = - pl08x_pre_boundary( - txd->dstbus.addr, - remainder); + pl08x_pre_boundary(txd->dstbus.addr, + target_len); else - txd->dstbus.fill_bytes = - max_bytes_per_lli; + txd->dstbus.fill_bytes = target_len; - /* - * Find the nearest - */ + /* Find the nearest */ lli_len = min(txd->srcbus.fill_bytes, txd->dstbus.fill_bytes); |