spi: sh-msiof: Make sure all DMA operations have completed
In case of a bi-directional transfer, receive DMA may complete in the
rcar-dmac driver before transmit DMA, due to scheduling latencies.
As the MSIOF driver waits for completion of the receive DMA only, it may
submit the next transmit DMA request before the previous one has
completed.
Make the driver more robust by waiting for the completion of both
receive and transmit DMA, when applicable.
Based on a patch in the BSP by Ryo Kataoka.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
(cherry picked from commit 08ba7ae35b15cd13b965d5fd5a835e0a0cb803e6)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c
index d1c51b4..5cec432 100644
--- a/drivers/spi/spi-sh-msiof.c
+++ b/drivers/spi/spi-sh-msiof.c
@@ -48,6 +48,7 @@
struct platform_device *pdev;
struct sh_msiof_spi_info *info;
struct completion done;
+ struct completion done_txdma;
unsigned int tx_fifo_size;
unsigned int rx_fifo_size;
unsigned int min_div_pow;
@@ -633,19 +634,21 @@
p->slave_aborted = true;
complete(&p->done);
+ complete(&p->done_txdma);
return 0;
}
-static int sh_msiof_wait_for_completion(struct sh_msiof_spi_priv *p)
+static int sh_msiof_wait_for_completion(struct sh_msiof_spi_priv *p,
+ struct completion *x)
{
if (spi_controller_is_slave(p->master)) {
- if (wait_for_completion_interruptible(&p->done) ||
+ if (wait_for_completion_interruptible(x) ||
p->slave_aborted) {
dev_dbg(&p->pdev->dev, "interrupted\n");
return -EINTR;
}
} else {
- if (!wait_for_completion_timeout(&p->done, HZ)) {
+ if (!wait_for_completion_timeout(x, HZ)) {
dev_err(&p->pdev->dev, "timeout\n");
return -ETIMEDOUT;
}
@@ -695,7 +698,7 @@
}
/* wait for tx fifo to be emptied / rx fifo to be filled */
- ret = sh_msiof_wait_for_completion(p);
+ ret = sh_msiof_wait_for_completion(p, &p->done);
if (ret)
goto stop_reset;
@@ -724,10 +727,7 @@
static void sh_msiof_dma_complete(void *arg)
{
- struct sh_msiof_spi_priv *p = arg;
-
- sh_msiof_write(p, IER, 0);
- complete(&p->done);
+ complete(arg);
}
static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
@@ -748,7 +748,7 @@
return -EAGAIN;
desc_rx->callback = sh_msiof_dma_complete;
- desc_rx->callback_param = p;
+ desc_rx->callback_param = &p->done;
cookie = dmaengine_submit(desc_rx);
if (dma_submit_error(cookie))
return cookie;
@@ -766,13 +766,8 @@
goto no_dma_tx;
}
- if (rx) {
- /* No callback */
- desc_tx->callback = NULL;
- } else {
- desc_tx->callback = sh_msiof_dma_complete;
- desc_tx->callback_param = p;
- }
+ desc_tx->callback = sh_msiof_dma_complete;
+ desc_tx->callback_param = &p->done_txdma;
cookie = dmaengine_submit(desc_tx);
if (dma_submit_error(cookie)) {
ret = cookie;
@@ -789,6 +784,8 @@
sh_msiof_write(p, IER, ier_bits);
reinit_completion(&p->done);
+ if (tx)
+ reinit_completion(&p->done_txdma);
p->slave_aborted = false;
/* Now start DMA */
@@ -803,17 +800,24 @@
goto stop_dma;
}
- /* wait for tx/rx DMA completion */
- ret = sh_msiof_wait_for_completion(p);
- if (ret)
- goto stop_reset;
+ if (tx) {
+ /* wait for tx DMA completion */
+ ret = sh_msiof_wait_for_completion(p, &p->done_txdma);
+ if (ret)
+ goto stop_reset;
+ }
- if (!rx) {
- reinit_completion(&p->done);
- sh_msiof_write(p, IER, IER_TEOFE);
+ if (rx) {
+ /* wait for rx DMA completion */
+ ret = sh_msiof_wait_for_completion(p, &p->done);
+ if (ret)
+ goto stop_reset;
+ sh_msiof_write(p, IER, 0);
+ } else {
/* wait for tx fifo to be emptied */
- ret = sh_msiof_wait_for_completion(p);
+ sh_msiof_write(p, IER, IER_TEOFE);
+ ret = sh_msiof_wait_for_completion(p, &p->done);
if (ret)
goto stop_reset;
}
@@ -1273,6 +1277,7 @@
p->min_div_pow = chipdata->min_div_pow;
init_completion(&p->done);
+ init_completion(&p->done_txdma);
p->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(p->clk)) {
