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| author | Dilip Kota <eswara.kota@linux.intel.com> | 2020-07-17 08:27:50 +0200 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2020-07-22 02:55:53 +0200 |
| commit | 661ccf2b3f1360be50242726f7c26ced6a9e7d52 (patch) | |
| tree | 5ad5d033ce56cbb46371143cb055e3c686ae7449 /drivers/spi/spi-lantiq-ssc.c | |
| parent | spi: spi-topcliff-pch: use generic power management (diff) | |
| download | linux-661ccf2b3f1360be50242726f7c26ced6a9e7d52.tar.xz linux-661ccf2b3f1360be50242726f7c26ced6a9e7d52.zip | |
spi: lantiq: fix: Rx overflow error in full duplex mode
In full duplex mode, rx overflow error is observed. To overcome the error,
wait until the complete data got received and proceed further.
Fixes: 17f84b793c01 ("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>
Diffstat (limited to 'drivers/spi/spi-lantiq-ssc.c')
| -rw-r--r-- | drivers/spi/spi-lantiq-ssc.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/spi/spi-lantiq-ssc.c b/drivers/spi/spi-lantiq-ssc.c index 1cf650e25e31..24585890996b 100644 --- a/drivers/spi/spi-lantiq-ssc.c +++ b/drivers/spi/spi-lantiq-ssc.c @@ -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); |