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SubjectRe: [PATCH v4 06/16] spi: dw: Parameterize the DMA Rx/Tx burst length
On Fri, May 22, 2020 at 03:07:55AM +0300, Serge Semin wrote:
> It isn't good to have numeric literals in the code especially if there
> are multiple of them and they are related. Let's replace the Tx and Rx
> burst level literals with the corresponding constants.


You missed my tag.

> Co-developed-by: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
> Signed-off-by: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
> Co-developed-by: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
> Signed-off-by: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: linux-mips@vger.kernel.org
> Cc: devicetree@vger.kernel.org
>
> ---
>
> Changelog v3:
> - Discard the dws->fifo_len utilization in the Tx FIFO DMA threshold
> setting.
> ---
> drivers/spi/spi-dw-mid.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c
> index c39bc8758339..1598c36c905f 100644
> --- a/drivers/spi/spi-dw-mid.c
> +++ b/drivers/spi/spi-dw-mid.c
> @@ -20,7 +20,9 @@
>
> #define WAIT_RETRIES 5
> #define RX_BUSY 0
> +#define RX_BURST_LEVEL 16
> #define TX_BUSY 1
> +#define TX_BURST_LEVEL 16
>
> static bool mid_spi_dma_chan_filter(struct dma_chan *chan, void *param)
> {
> @@ -198,7 +200,7 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_tx(struct dw_spi *dws,
> memset(&txconf, 0, sizeof(txconf));
> txconf.direction = DMA_MEM_TO_DEV;
> txconf.dst_addr = dws->dma_addr;
> - txconf.dst_maxburst = 16;
> + txconf.dst_maxburst = TX_BURST_LEVEL;
> txconf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> txconf.dst_addr_width = convert_dma_width(dws->n_bytes);
> txconf.device_fc = false;
> @@ -273,7 +275,7 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws,
> memset(&rxconf, 0, sizeof(rxconf));
> rxconf.direction = DMA_DEV_TO_MEM;
> rxconf.src_addr = dws->dma_addr;
> - rxconf.src_maxburst = 16;
> + rxconf.src_maxburst = RX_BURST_LEVEL;
> rxconf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> rxconf.src_addr_width = convert_dma_width(dws->n_bytes);
> rxconf.device_fc = false;
> @@ -298,8 +300,8 @@ static int mid_spi_dma_setup(struct dw_spi *dws, struct spi_transfer *xfer)
> {
> u16 imr = 0, dma_ctrl = 0;
>
> - dw_writel(dws, DW_SPI_DMARDLR, 0xf);
> - dw_writel(dws, DW_SPI_DMATDLR, 0x10);
> + dw_writel(dws, DW_SPI_DMARDLR, RX_BURST_LEVEL - 1);
> + dw_writel(dws, DW_SPI_DMATDLR, TX_BURST_LEVEL);
>
> if (xfer->tx_buf) {
> dma_ctrl |= SPI_DMA_TDMAE;
> --
> 2.25.1
>

--
With Best Regards,
Andy Shevchenko


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