From 8b30afb00537eb479cae6cae758765c3c874bb8f Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Fri, 4 Dec 2015 20:26:22 +0000 Subject: [PATCH] lantiq: fix a race condition in the SPI driver leading to rx FIFO overflows (and subsequent timeouts) Signed-off-by: Felix Fietkau SVN-Revision: 47770 --- .../0033-SPI-MIPS-lantiq-adds-spi-xway.patch | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/target/linux/lantiq/patches-4.1/0033-SPI-MIPS-lantiq-adds-spi-xway.patch b/target/linux/lantiq/patches-4.1/0033-SPI-MIPS-lantiq-adds-spi-xway.patch index 956dd10368..93a2972599 100644 --- a/target/linux/lantiq/patches-4.1/0033-SPI-MIPS-lantiq-adds-spi-xway.patch +++ b/target/linux/lantiq/patches-4.1/0033-SPI-MIPS-lantiq-adds-spi-xway.patch @@ -42,7 +42,7 @@ Signed-off-by: John Crispin +obj-$(CONFIG_SPI_XWAY) += spi-xway.o --- /dev/null +++ b/drivers/spi/spi-xway.c -@@ -0,0 +1,991 @@ +@@ -0,0 +1,1003 @@ +/* + * Lantiq SoC SPI controller + * @@ -667,10 +667,22 @@ Signed-off-by: John Crispin +static void ltq_spi_rxreq_set(struct ltq_spi *hw) +{ + u32 rxreq, rxreq_max, rxtodo; ++ u32 fstat, fifo_fill; + + rxtodo = ltq_spi_reg_read(hw, LTQ_SPI_RXCNT) & LTQ_SPI_RXCNT_TODO_MASK; + + /* ++ * Check if there is remaining data in the FIFO before starting a new ++ * receive request. The controller might have processed some more data ++ * since the last FIFO poll. ++ */ ++ fstat = ltq_spi_reg_read(hw, LTQ_SPI_FSTAT); ++ fifo_fill = ((fstat >> LTQ_SPI_FSTAT_RXFFL_SHIFT) ++ & LTQ_SPI_FSTAT_RXFFL_MASK); ++ if (fifo_fill) ++ return; ++ ++ /* + * In RX-only mode the serial clock is activated only after writing + * the expected amount of RX bytes into RXREQ register. + * To avoid receive overflows at high clocks it is better to request -- 2.30.2