From 0cf101d6b39a10952420af0f300a0784190887ff Mon Sep 17 00:00:00 2001 From: Tim Harvey Date: Thu, 28 May 2020 07:58:49 -0700 Subject: [PATCH] octeontx: fix mcp251x can controller Update the can-mcp251x-convert-to-half-duplex-SPI patch to fix reception Some SPI host controllers such as the Cavium Thunder TX do not support full-duplex SPI. Using half-duplex transfers allows the driver to work with those host controllers. This patch fixes the fact that mcp251x_hw_rx_frame was still relying on a full-duplex transfer where bits were being shifted on MOSI at the same time as MISO. After splitting the transaction into a spi_write_then_read() care must be taken to ignore the first byte. Signed-off-by: Tim Harvey --- ...n-mcp251x-convert-to-half-duplex-SPI.patch | 31 ++++++++++++++----- 1 file changed, 24 insertions(+), 7 deletions(-) diff --git a/target/linux/octeontx/patches-5.4/0003-can-mcp251x-convert-to-half-duplex-SPI.patch b/target/linux/octeontx/patches-5.4/0003-can-mcp251x-convert-to-half-duplex-SPI.patch index 6096fcf2be..54906b786e 100644 --- a/target/linux/octeontx/patches-5.4/0003-can-mcp251x-convert-to-half-duplex-SPI.patch +++ b/target/linux/octeontx/patches-5.4/0003-can-mcp251x-convert-to-half-duplex-SPI.patch @@ -1,20 +1,22 @@ -From 6edfb172ff1dd3cfc84c19790c245a4005474bb7 Mon Sep 17 00:00:00 2001 +From 097cc81ee5c15913ad330baffff2e3dea09bdad0 Mon Sep 17 00:00:00 2001 From: Tim Harvey -Date: Tue, 25 Feb 2020 12:01:36 -0800 -Subject: [PATCH 03/12] can: mcp251x: convert to half-duplex SPI +Date: Thu, 30 Aug 2018 15:16:08 -0700 +Subject: [PATCH] can: mcp251x: convert driver to half-duplex SPI -Some SPI host controllers such as the Cavium Thunder do not support +Some SPI host controllers such as the Cavium Thunder TX do not support full-duplex SPI. Using half-duplex transfers allows the driver to work with those host controllers. Signed-off-by: Tim Harvey --- - drivers/net/can/spi/mcp251x.c | 10 +++++----- - 1 file changed, 5 insertions(+), 5 deletions(-) + drivers/net/can/spi/mcp251x.c | 15 ++++++++------- + 1 file changed, 8 insertions(+), 7 deletions(-) +diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c +index bb20a9b..dc0574a 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c -@@ -291,23 +291,23 @@ static u8 mcp251x_read_reg(struct spi_de +@@ -291,23 +291,23 @@ static u8 mcp251x_read_reg(struct spi_device *spi, u8 reg) priv->spi_tx_buf[0] = INSTRUCTION_READ; priv->spi_tx_buf[1] = reg; @@ -43,3 +45,18 @@ Signed-off-by: Tim Harvey } static void mcp251x_write_reg(struct spi_device *spi, u8 reg, u8 val) +@@ -398,8 +398,9 @@ static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf, + buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i); + } else { + priv->spi_tx_buf[RXBCTRL_OFF] = INSTRUCTION_READ_RXB(buf_idx); +- mcp251x_spi_trans(spi, SPI_TRANSFER_BUF_LEN); +- memcpy(buf, priv->spi_rx_buf, SPI_TRANSFER_BUF_LEN); ++ spi_write_then_read(spi, priv->spi_tx_buf, 1, priv->spi_rx_buf, ++ SPI_TRANSFER_BUF_LEN); ++ memcpy(buf + 1, priv->spi_rx_buf, SPI_TRANSFER_BUF_LEN - 1); + } + } + +-- +2.7.4 + -- 2.25.1