Re: [PATCH v2 08/19] spi: dw: Discard dma_width member of the dw_spi structure
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: 2020-05-15 13:03:19
Also in:
linux-mips, linux-spi, lkml
On Fri, May 15, 2020 at 01:47:47PM +0300, Serge Semin wrote:
This member has exactly the same value as n_bytes of the DW SPI private data object, it's calculated at the same point of the transfer method, n_bytes isn't changed during the whole transfer, and they even serve for the same purpose - keep number of bytes per transfer word, though the dma_width is used only to calculate the DMA source/destination addresses width, which n_bytes could be also utilized for. Taking all of these into account let's replace the dma_width member usage with n_bytes one and remove the former.
I've no strong opinion about this. So, after addressing one issue below, Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
quoted hunk
Signed-off-by: Serge Semin <redacted> Cc: Georgy Vlasov <redacted> Cc: Ramil Zaripov <redacted> Cc: Alexey Malahov <redacted> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Paul Burton <paulburton@kernel.org> Cc: Ralf Baechle <redacted> Cc: Allison Randal <redacted> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Gareth Williams <redacted> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org --- Changelog v2: - It's a new patch created as a result of more thorough driver study. --- drivers/spi/spi-dw-mid.c | 10 +++++----- drivers/spi/spi-dw.c | 1 - drivers/spi/spi-dw.h | 1 - 3 files changed, 5 insertions(+), 7 deletions(-)diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c index be886e22a1b1..ca8813a693d8 100644 --- a/drivers/spi/spi-dw-mid.c +++ b/drivers/spi/spi-dw-mid.c@@ -132,10 +132,10 @@ static bool mid_spi_can_dma(struct spi_controller *master, return xfer->len > dws->fifo_len; } -static enum dma_slave_buswidth convert_dma_width(u32 dma_width) { - if (dma_width == 1)
+static enum dma_slave_buswidth convert_dma_width(u8 n_bytes) {
It seems somebody (maybe even me) at some point messed up between enum
definition and function that returns an enum.
For what said, { should be on the separate line.
quoted hunk
+ if (n_bytes == 1) return DMA_SLAVE_BUSWIDTH_1_BYTE; - else if (dma_width == 2) + else if (n_bytes == 2) return DMA_SLAVE_BUSWIDTH_2_BYTES; return DMA_SLAVE_BUSWIDTH_UNDEFINED;@@ -195,7 +195,7 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_tx(struct dw_spi *dws, txconf.dst_addr = dws->dma_addr; txconf.dst_maxburst = 16; txconf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; - txconf.dst_addr_width = convert_dma_width(dws->dma_width); + txconf.dst_addr_width = convert_dma_width(dws->n_bytes); txconf.device_fc = false; dmaengine_slave_config(dws->txchan, &txconf);@@ -268,7 +268,7 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws, rxconf.src_addr = dws->dma_addr; rxconf.src_maxburst = 16; rxconf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; - rxconf.src_addr_width = convert_dma_width(dws->dma_width); + rxconf.src_addr_width = convert_dma_width(dws->n_bytes); rxconf.device_fc = false; dmaengine_slave_config(dws->rxchan, &rxconf);diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c index 450c8218caeb..1edb8cdd11ee 100644 --- a/drivers/spi/spi-dw.c +++ b/drivers/spi/spi-dw.c@@ -353,7 +353,6 @@ static int dw_spi_transfer_one(struct spi_controller *master, } dws->n_bytes = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE); - dws->dma_width = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE); cr0 = dws->update_cr0(master, spi, transfer); dw_writel(dws, DW_SPI_CTRLR0, cr0);diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h index b6ab81e0c747..4902f937c3d7 100644 --- a/drivers/spi/spi-dw.h +++ b/drivers/spi/spi-dw.h@@ -136,7 +136,6 @@ struct dw_spi { void *rx_end; int dma_mapped; u8 n_bytes; /* current is a 1/2 bytes op */ - u32 dma_width; irqreturn_t (*transfer_handler)(struct dw_spi *dws); u32 current_freq; /* frequency in hz */-- 2.25.1
-- With Best Regards, Andy Shevchenko