From: Robin Gong <yibin.gong@nxp.com>
Date: Wed, 10 Oct 2018 10:32:48 +0000 (+0000)
Subject: spi: imx: use PIO mode if size is small
X-Git-Tag: v4.20-rc1~185^2~1^2~9
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=133eb8e38b02c6c63a039523fca12737009a6686;p=thirdparty%2Fkernel%2Flinux.git

spi: imx: use PIO mode if size is small

Use PIO mode instead if size is smaller than fifo size, since
dma may be less efficient.

Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 037abbb852a4d..dd1ce12aa386a 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -224,6 +224,9 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 	if (spi_imx->slave_mode)
 		return false;
 
+	if (transfer->len < spi_imx->devtype_data->fifo_size)
+		return false;
+
 	spi_imx->dynamic_burst = 0;
 
 	return true;