| Message ID | 1418763946-22260-3-git-send-email-abrestic@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Dec 16, 2014 at 01:05:46PM -0800, Andrew Bresticker wrote: > A 1-byte burst size is rather inefficient and has been shown to cause > TX issues during testing. Increase the DMA burst size to 4-bytes for > both RX and TX DMA when using the 8-bit FIFO. This sounds like a fix for transmit issues so should go before patch 2 (which seems like it is a performance improvement rather than a bug fix) but it depends on that patch - can you respin in the opposite order please?
On Mon, Dec 22, 2014 at 9:54 AM, Mark Brown <broonie@kernel.org> wrote: > > On Tue, Dec 16, 2014 at 01:05:46PM -0800, Andrew Bresticker wrote: > > > A 1-byte burst size is rather inefficient and has been shown to cause > > TX issues during testing. Increase the DMA burst size to 4-bytes for > > both RX and TX DMA when using the 8-bit FIFO. > > This sounds like a fix for transmit issues so should go before patch 2 > (which seems like it is a performance improvement rather than a bug fix) > but it depends on that patch - can you respin in the opposite order > please? Yes, will do. -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/spi/spi-img-spfi.c b/drivers/spi/spi-img-spfi.c index 2b29df0..29b97f8 100644 --- a/drivers/spi/spi-img-spfi.c +++ b/drivers/spi/spi-img-spfi.c @@ -336,7 +336,7 @@ static int img_spfi_start_dma(struct spi_master *master, } else { rxconf.src_addr = spfi->phys + SPFI_RX_8BIT_VALID_DATA; rxconf.src_addr_width = 1; - rxconf.src_maxburst = 1; + rxconf.src_maxburst = 4; } dmaengine_slave_config(spfi->rx_ch, &rxconf); @@ -360,7 +360,7 @@ static int img_spfi_start_dma(struct spi_master *master, } else { txconf.dst_addr = spfi->phys + SPFI_TX_8BIT_VALID_DATA; txconf.dst_addr_width = 1; - txconf.dst_maxburst = 1; + txconf.dst_maxburst = 4; } dmaengine_slave_config(spfi->tx_ch, &txconf);
A 1-byte burst size is rather inefficient and has been shown to cause TX issues during testing. Increase the DMA burst size to 4-bytes for both RX and TX DMA when using the 8-bit FIFO. Signed-off-by: Andrew Bresticker <abrestic@chromium.org> --- drivers/spi/spi-img-spfi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)