From dbbdc81c6064b4cb7ffc796b71713a19488a2c4c Mon Sep 17 00:00:00 2001 From: Jagan Teki Date: Sat, 21 Dec 2019 13:24:30 +0530 Subject: [PATCH] spi: rk: Limit transfers to (64K - 1) bytes The Rockchip SPI controller's length register only supports 16-bits, yielding a maximum length of 64KiB (the CTRLR1 register holds "length - 1"). Trying to transfer more than that (e.g., with a large SPI flash read) will cause the driver to hang. Now, it seems that while theoretically we should be able to program CTRLR1 with 0xffff, and get a 64KiB transfer, but that also seems to cause the core to choke, so stick with a maximum of 64K - 1 bytes -- i.e., 0xffff. Note, that the size is further divided into 'minus 1' while writing into CTRLR1. This change fixed two different read issues, 1. sf read failure when with > 0x10000 2. Boot from SPI flash failed during spi_flash_read call in common/spl/spl_spi.c Observed and Tested in - Rockpro64 with Gigadevice flash - ROC-RK3399-PC with Winbond flash Signed-off-by: Jagan Teki Reviewed-by: Kever Yang --- drivers/spi/rk_spi.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/spi/rk_spi.c b/drivers/spi/rk_spi.c index c04535ac44..95eeb8307a 100644 --- a/drivers/spi/rk_spi.c +++ b/drivers/spi/rk_spi.c @@ -27,6 +27,12 @@ /* Change to 1 to output registers at the start of each transaction */ #define DEBUG_RK_SPI 0 +/* + * ctrlr1 is 16-bits, so we should support lengths of 0xffff + 1. However, + * the controller seems to hang when given 0x10000, so stick with this for now. + */ +#define ROCKCHIP_SPI_MAX_TRANLEN 0xffff + struct rockchip_spi_params { /* RXFIFO overruns and TXFIFO underruns stop the master clock */ bool master_manages_fifo; @@ -367,7 +373,7 @@ static inline int rockchip_spi_16bit_reader(struct udevice *dev, * represented in CTRLR1. */ if (data && data->master_manages_fifo) - max_chunk_size = 0x10000; + max_chunk_size = ROCKCHIP_SPI_MAX_TRANLEN; // rockchip_spi_configure(dev, mode, size) rkspi_enable_chip(regs, false); @@ -451,7 +457,7 @@ static int rockchip_spi_xfer(struct udevice *dev, unsigned int bitlen, /* This is the original 8bit reader/writer code */ while (len > 0) { - int todo = min(len, 0x10000); + int todo = min(len, ROCKCHIP_SPI_MAX_TRANLEN); rkspi_enable_chip(regs, false); writel(todo - 1, ®s->ctrlr1); -- 2.39.2