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authorAmelie Delaunay <amelie.delaunay@st.com>2017-06-27 11:45:19 -0400
committerMark Brown <broonie@kernel.org>2017-06-28 15:00:54 -0400
commitc67ad368cf75d4999d5ef86543d082b4b35dd2d7 (patch)
tree354413e8bf60d547b45eadc280bb93fbb1ace01e
parent038ac869c9d27fceb6197e775d780ad6aeb45b1f (diff)
spi: stm32: enhance DMA error management
This patch reworks DMA error management. In case the DMA callback is called while EOT (End Of Transfer) flag is not set, that means that DMA encountered an error. This error will result in an auto-suspend of SPI flow, which could also result in an overrun. So, in DMA mode, SUSP and OVR flags are a condition to stop the current transfer. Moreover, stm32_spi_can_dma doesn't care about the state of dma channels. During driver probe, master->can_dma is initialised if dma channel request is successful. That's why we must use master->can_dma to know if dma use is possible (dma channel are successfully requested and the transfer size is greater than fifo size). Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com> Signed-off-by: Mark Brown <broonie@kernel.org>
-rw-r--r--drivers/spi/spi-stm32.c23
1 files changed, 17 insertions, 6 deletions
diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index 392c9453c2e6..8a6bff379b21 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -514,6 +514,12 @@ static irqreturn_t stm32_spi_irq(int irq, void *dev_id)
514 dev_warn(spi->dev, "Communication suspended\n"); 514 dev_warn(spi->dev, "Communication suspended\n");
515 if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0))) 515 if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
516 stm32_spi_read_rxfifo(spi, false); 516 stm32_spi_read_rxfifo(spi, false);
517 /*
518 * If communication is suspended while using DMA, it means
519 * that something went wrong, so stop the current transfer
520 */
521 if (spi->cur_usedma)
522 end = true;
517 } 523 }
518 524
519 if (sr & SPI_SR_MODF) { 525 if (sr & SPI_SR_MODF) {
@@ -525,6 +531,12 @@ static irqreturn_t stm32_spi_irq(int irq, void *dev_id)
525 dev_warn(spi->dev, "Overrun: received value discarded\n"); 531 dev_warn(spi->dev, "Overrun: received value discarded\n");
526 if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0))) 532 if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
527 stm32_spi_read_rxfifo(spi, false); 533 stm32_spi_read_rxfifo(spi, false);
534 /*
535 * If overrun is detected while using DMA, it means that
536 * something went wrong, so stop the current transfer
537 */
538 if (spi->cur_usedma)
539 end = true;
528 } 540 }
529 541
530 if (sr & SPI_SR_EOT) { 542 if (sr & SPI_SR_EOT) {
@@ -645,12 +657,10 @@ static void stm32_spi_dma_cb(void *data)
645 657
646 spin_unlock_irqrestore(&spi->lock, flags); 658 spin_unlock_irqrestore(&spi->lock, flags);
647 659
648 if (!(sr & SPI_SR_EOT)) { 660 if (!(sr & SPI_SR_EOT))
649 dev_warn(spi->dev, "DMA callback (sr=0x%08x)\n", sr); 661 dev_warn(spi->dev, "DMA error (sr=0x%08x)\n", sr);
650 662
651 spi_finalize_current_transfer(spi->master); 663 /* Now wait for EOT, or SUSP or OVR in case of error */
652 stm32_spi_disable(spi);
653 }
654} 664}
655 665
656/** 666/**
@@ -986,7 +996,8 @@ static int stm32_spi_transfer_one(struct spi_master *master,
986 spi->tx_len = spi->tx_buf ? transfer->len : 0; 996 spi->tx_len = spi->tx_buf ? transfer->len : 0;
987 spi->rx_len = spi->rx_buf ? transfer->len : 0; 997 spi->rx_len = spi->rx_buf ? transfer->len : 0;
988 998
989 spi->cur_usedma = stm32_spi_can_dma(master, spi_dev, transfer); 999 spi->cur_usedma = (master->can_dma &&
1000 stm32_spi_can_dma(master, spi_dev, transfer));
990 1001
991 ret = stm32_spi_transfer_one_setup(spi, spi_dev, transfer); 1002 ret = stm32_spi_transfer_one_setup(spi, spi_dev, transfer);
992 if (ret) { 1003 if (ret) {