mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-08-21 00:10:09 +00:00
Code Issues Releases Wiki Activity

spi: sh-msiof: Use DMA if possible

Browse source 
Currently, this driver only supports feature for DMA 32-bits.
In this case, only if the data length is divisible by 4 to use
DMA, otherwise PIO will be used. This patch will suggest use
the DMA 32-bits with 4bytes of words, then the remaining data
will be transmitted by PIO mode.

Signed-off-by: Hoan Nguyen An <na-hoan@jinso.co.jp>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Hoan Nguyen An 2019-01-18 18:29:31 +09:00 committed by Mark Brown
parent f70351ae06
commit d05e3eadb1
No known key found for this signature in database
GPG key ID: 24D68B725D5487D0
1 changed files with 2 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
drivers/spi/spi-sh-msiof.c
View file

@ -937,17 +937,13 @@ static int sh_msiof_transfer_one(struct spi_master *master,
unsigned int l = 0;
if (tx_buf)
l = min(len, p->tx_fifo_size * 4);
l = min(round_down(len, 4), p->tx_fifo_size * 4);
if (rx_buf)
l = min(len, p->rx_fifo_size * 4);
l = min(round_down(len, 4), p->rx_fifo_size * 4);
if (bits <= 8) {
if (l & 3)
break;
copy32 = copy_bswap32;
} else if (bits <= 16) {
if (l & 3)
break;
copy32 = copy_wswap32;
} else {
copy32 = copy_plain32;