The patch spi: spi-s3c64xx: Allow higher transfer lengths in polling IO mode has been applied to the spi tree at https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark >From 0af7af7da6510f12595b81ba98bb15dd7ffed1f3 Mon Sep 17 00:00:00 2001 From: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx> Date: Tue, 17 Apr 2018 16:29:54 +0200 Subject: [PATCH] spi: spi-s3c64xx: Allow higher transfer lengths in polling IO mode Some variants of the SPI controller have no DMA support, in such case SPI transfers longer than the FIFO length are not currently properly handled by the driver. Fix it by doing multiple transfers in the s3c64xx_spi_transfer_one() function if the SPI transfer length exceeds the FIFO size. Signed-off-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx> Reviewed-by: Andi Shyti <andi@xxxxxxxxxxx> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> --- drivers/spi/spi-s3c64xx.c | 99 ++++++++++++++++++++++++++------------- 1 file changed, 66 insertions(+), 33 deletions(-) diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 27cd8c59eabf..755ab2dc6969 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -635,11 +635,14 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master, { struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master); const unsigned int fifo_len = (FIFO_LVL_MASK(sdd) >> 1) + 1; + const void *tx_buf = NULL; + void *rx_buf = NULL; + int target_len = 0, origin_len = 0; + int use_dma = 0; int status; u32 speed; u8 bpw; unsigned long flags; - int use_dma; reinit_completion(&sdd->xfer_completion); @@ -654,47 +657,77 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master, s3c64xx_spi_config(sdd); } - /* Polling method for xfers not bigger than FIFO capacity */ - use_dma = 0; if (!is_polling(sdd) && (xfer->len > fifo_len) && - sdd->rx_dma.ch && sdd->tx_dma.ch) + sdd->rx_dma.ch && sdd->tx_dma.ch) { use_dma = 1; - spin_lock_irqsave(&sdd->lock, flags); + } else if (is_polling(sdd) && xfer->len > fifo_len) { + tx_buf = xfer->tx_buf; + rx_buf = xfer->rx_buf; + origin_len = xfer->len; - /* Pending only which is to be done */ - sdd->state &= ~RXBUSY; - sdd->state &= ~TXBUSY; + target_len = xfer->len; + if (xfer->len > fifo_len) + xfer->len = fifo_len; + } + + do { + spin_lock_irqsave(&sdd->lock, flags); - s3c64xx_enable_datapath(sdd, xfer, use_dma); + /* Pending only which is to be done */ + sdd->state &= ~RXBUSY; + sdd->state &= ~TXBUSY; - /* Start the signals */ - s3c64xx_spi_set_cs(spi, true); + s3c64xx_enable_datapath(sdd, xfer, use_dma); - spin_unlock_irqrestore(&sdd->lock, flags); + /* Start the signals */ + s3c64xx_spi_set_cs(spi, true); - if (use_dma) - status = s3c64xx_wait_for_dma(sdd, xfer); - else - status = s3c64xx_wait_for_pio(sdd, xfer); - - if (status) { - dev_err(&spi->dev, "I/O Error: rx-%d tx-%d res:rx-%c tx-%c len-%d\n", - xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0, - (sdd->state & RXBUSY) ? 'f' : 'p', - (sdd->state & TXBUSY) ? 'f' : 'p', - xfer->len); - - if (use_dma) { - if (xfer->tx_buf != NULL - && (sdd->state & TXBUSY)) - dmaengine_terminate_all(sdd->tx_dma.ch); - if (xfer->rx_buf != NULL - && (sdd->state & RXBUSY)) - dmaengine_terminate_all(sdd->rx_dma.ch); + spin_unlock_irqrestore(&sdd->lock, flags); + + if (use_dma) + status = s3c64xx_wait_for_dma(sdd, xfer); + else + status = s3c64xx_wait_for_pio(sdd, xfer); + + if (status) { + dev_err(&spi->dev, + "I/O Error: rx-%d tx-%d res:rx-%c tx-%c len-%d\n", + xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0, + (sdd->state & RXBUSY) ? 'f' : 'p', + (sdd->state & TXBUSY) ? 'f' : 'p', + xfer->len); + + if (use_dma) { + if (xfer->tx_buf && (sdd->state & TXBUSY)) + dmaengine_terminate_all(sdd->tx_dma.ch); + if (xfer->rx_buf && (sdd->state & RXBUSY)) + dmaengine_terminate_all(sdd->rx_dma.ch); + } + } else { + s3c64xx_flush_fifo(sdd); } - } else { - s3c64xx_flush_fifo(sdd); + if (target_len > 0) { + target_len -= xfer->len; + + if (xfer->tx_buf) + xfer->tx_buf += xfer->len; + + if (xfer->rx_buf) + xfer->rx_buf += xfer->len; + + if (target_len > fifo_len) + xfer->len = fifo_len; + else + xfer->len = target_len; + } + } while (target_len > 0); + + if (origin_len) { + /* Restore original xfer buffers and length */ + xfer->tx_buf = tx_buf; + xfer->rx_buf = rx_buf; + xfer->len = origin_len; } return status; -- 2.17.0 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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