spi: lantiq: fix: Rx overflow error in full duplex mode (661ccf2b) · Commits · 戴 / test

In full duplex mode, rx overflow error is observed. To overcome the error, wait until the complete data got received and proceed further. Fixes: ("spi: lantiq-ssc: add support for Lantiq SSC SPI controller") Signed-off-by:

Dilip Kota <eswara.kota@linux.intel.com> Link: https://lore.kernel.org/r/efb650b0faa49a00788c4e0ca8ef7196bdba851d.1594957019.git.eswara.kota@linux.intel.com Signed-off-by:

Mark Brown <broonie@kernel.org>

drivers/spi/spi-lantiq-ssc.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -183,6 +183,7 @@ struct lantiq_ssc_spi {
		unsigned int tx_fifo_size;
		unsigned int rx_fifo_size;
		unsigned int base_cs;
		unsigned int fdx_tx_level;
		};

		static u32 lantiq_ssc_readl(const struct lantiq_ssc_spi *spi, u32 reg)
		@@ -480,6 +481,7 @@ static void tx_fifo_write(struct lantiq_ssc_spi *spi)
		u32 data;
		unsigned int tx_free = tx_fifo_free(spi);

		spi->fdx_tx_level = 0;
		while (spi->tx_todo && tx_free) {
		switch (spi->bits_per_word) {
		case 2 ... 8:
		@@ -508,6 +510,7 @@ static void tx_fifo_write(struct lantiq_ssc_spi *spi)

		lantiq_ssc_writel(spi, data, LTQ_SPI_TB);
		tx_free--;
		spi->fdx_tx_level++;
		}
		}

		@@ -519,6 +522,13 @@ static void rx_fifo_read_full_duplex(struct lantiq_ssc_spi *spi)
		u32 data;
		unsigned int rx_fill = rx_fifo_level(spi);

		/*
		* Wait until all expected data to be shifted in.
		* Otherwise, rx overrun may occur.
		*/
		while (rx_fill != spi->fdx_tx_level)
		rx_fill = rx_fifo_level(spi);

		while (rx_fill) {
		data = lantiq_ssc_readl(spi, LTQ_SPI_RB);

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