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| author | Robin Gong <yibin.gong@nxp.com> | 2020-06-17 06:42:08 +0800 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2020-06-23 13:38:14 +0100 |
| commit | 809b1b04df898b6d182069146231a3cbf5f2d9cc (patch) | |
| tree | 64458c4970bab1cdccef890aa54f6267fa28c346 /drivers/spi/spi.c | |
| parent | c314360cea42e9481d9f68a73a3a776eba31ba4b (diff) | |
| download | linux-809b1b04df898b6d182069146231a3cbf5f2d9cc.tar.bz2 | |
spi: introduce fallback to pio
Add fallback to pio mode in case dma transfer failed with error status
SPI_TRANS_FAIL_NO_START.
If spi client driver want to enable this feature please set xfer->error in
the proper place such as dmaengine_prep_slave_sg() failure detect(but no
any data put into spi bus yet). Besides, add master->fallback checking in
its can_dma() so that spi core could switch to pio next time. Please refer
to spi-imx.c.
Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Link: https://lore.kernel.org/r/1592347329-28363-2-git-send-email-yibin.gong@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi.c')
| -rw-r--r-- | drivers/spi/spi.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 8158e281f354..6fa56590bba2 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -982,6 +982,8 @@ static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg) spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE); } + ctlr->cur_msg_mapped = false; + return 0; } #else /* !CONFIG_HAS_DMA */ @@ -1234,8 +1236,17 @@ static int spi_transfer_one_message(struct spi_controller *ctlr, if (xfer->tx_buf || xfer->rx_buf) { reinit_completion(&ctlr->xfer_completion); +fallback_pio: ret = ctlr->transfer_one(ctlr, msg->spi, xfer); if (ret < 0) { + if (ctlr->cur_msg_mapped && + (xfer->error & SPI_TRANS_FAIL_NO_START)) { + __spi_unmap_msg(ctlr, msg); + ctlr->fallback = true; + xfer->error &= ~SPI_TRANS_FAIL_NO_START; + goto fallback_pio; + } + SPI_STATISTICS_INCREMENT_FIELD(statm, errors); SPI_STATISTICS_INCREMENT_FIELD(stats, @@ -1693,6 +1704,7 @@ void spi_finalize_current_message(struct spi_controller *ctlr) spin_lock_irqsave(&ctlr->queue_lock, flags); ctlr->cur_msg = NULL; ctlr->cur_msg_prepared = false; + ctlr->fallback = false; kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages); spin_unlock_irqrestore(&ctlr->queue_lock, flags); |