From: Sowjanya Komatineni skomatineni@nvidia.com
[ Upstream commit f4ce428c41fb22e3ed55496dded94df44cb920fa ]
Fixes: Configure DMA burst size to be same as SPI TX/RX trigger levels to avoid mismatch.
SPI FIFO trigger levels are calculated based on the transfer length. So this patch moves DMA slave configuration to happen before start of DMAs.
Signed-off-by: Sowjanya Komatineni skomatineni@nvidia.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi-tegra114.c | 52 ++++++++++++++++++++++---------------- 1 file changed, 30 insertions(+), 22 deletions(-)
diff --git a/drivers/spi/spi-tegra114.c b/drivers/spi/spi-tegra114.c index 5114b80084722..09cfae3abce2d 100644 --- a/drivers/spi/spi-tegra114.c +++ b/drivers/spi/spi-tegra114.c @@ -529,6 +529,8 @@ static int tegra_spi_start_dma_based_transfer( u32 val; unsigned int len; int ret = 0; + u8 dma_burst; + struct dma_slave_config dma_sconfig = {0};
val = SPI_DMA_BLK_SET(tspi->curr_dma_words - 1); tegra_spi_writel(tspi, val, SPI_DMA_BLK); @@ -540,12 +542,16 @@ static int tegra_spi_start_dma_based_transfer( len = tspi->curr_dma_words * 4;
/* Set attention level based on length of transfer */ - if (len & 0xF) + if (len & 0xF) { val |= SPI_TX_TRIG_1 | SPI_RX_TRIG_1; - else if (((len) >> 4) & 0x1) + dma_burst = 1; + } else if (((len) >> 4) & 0x1) { val |= SPI_TX_TRIG_4 | SPI_RX_TRIG_4; - else + dma_burst = 4; + } else { val |= SPI_TX_TRIG_8 | SPI_RX_TRIG_8; + dma_burst = 8; + }
if (tspi->cur_direction & DATA_DIR_TX) val |= SPI_IE_TX; @@ -556,7 +562,18 @@ static int tegra_spi_start_dma_based_transfer( tegra_spi_writel(tspi, val, SPI_DMA_CTL); tspi->dma_control_reg = val;
+ dma_sconfig.device_fc = true; if (tspi->cur_direction & DATA_DIR_TX) { + dma_sconfig.dst_addr = tspi->phys + SPI_TX_FIFO; + dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + dma_sconfig.dst_maxburst = dma_burst; + ret = dmaengine_slave_config(tspi->tx_dma_chan, &dma_sconfig); + if (ret < 0) { + dev_err(tspi->dev, + "DMA slave config failed: %d\n", ret); + return ret; + } + tegra_spi_copy_client_txbuf_to_spi_txbuf(tspi, t); ret = tegra_spi_start_tx_dma(tspi, len); if (ret < 0) { @@ -567,6 +584,16 @@ static int tegra_spi_start_dma_based_transfer( }
if (tspi->cur_direction & DATA_DIR_RX) { + dma_sconfig.src_addr = tspi->phys + SPI_RX_FIFO; + dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + dma_sconfig.src_maxburst = dma_burst; + ret = dmaengine_slave_config(tspi->rx_dma_chan, &dma_sconfig); + if (ret < 0) { + dev_err(tspi->dev, + "DMA slave config failed: %d\n", ret); + return ret; + } + /* Make the dma buffer to read by dma */ dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys, tspi->dma_buf_size, DMA_FROM_DEVICE); @@ -626,7 +653,6 @@ static int tegra_spi_init_dma_param(struct tegra_spi_data *tspi, u32 *dma_buf; dma_addr_t dma_phys; int ret; - struct dma_slave_config dma_sconfig;
dma_chan = dma_request_slave_channel_reason(tspi->dev, dma_to_memory ? "rx" : "tx"); @@ -646,19 +672,6 @@ static int tegra_spi_init_dma_param(struct tegra_spi_data *tspi, return -ENOMEM; }
- if (dma_to_memory) { - dma_sconfig.src_addr = tspi->phys + SPI_RX_FIFO; - dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; - dma_sconfig.src_maxburst = 0; - } else { - dma_sconfig.dst_addr = tspi->phys + SPI_TX_FIFO; - dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; - dma_sconfig.dst_maxburst = 0; - } - - ret = dmaengine_slave_config(dma_chan, &dma_sconfig); - if (ret) - goto scrub; if (dma_to_memory) { tspi->rx_dma_chan = dma_chan; tspi->rx_dma_buf = dma_buf; @@ -669,11 +682,6 @@ static int tegra_spi_init_dma_param(struct tegra_spi_data *tspi, tspi->tx_dma_phys = dma_phys; } return 0; - -scrub: - dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys); - dma_release_channel(dma_chan); - return ret; }
static void tegra_spi_deinit_dma_param(struct tegra_spi_data *tspi,