6.5-stable review patch. If anyone has any objections, please let me know.
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From: Valentin Caron valentin.caron@foss.st.com
[ Upstream commit 6de8a70c84ee0586fdde4e671626b9caca6aed74 ]
As explained in errata sheet, in section "2.14.5 Truncation of SPI output signals after EOT event": On STM32MP1x, EOT interrupt can be thrown before the true end of communication.
So we add a delay of a half period to wait the real end of the transmission.
Link: https://www.st.com/resource/en/errata_sheet/es0539-stm32mp131x3x5x-device-er... Signed-off-by: Valentin Caron valentin.caron@foss.st.com Link: https://lore.kernel.org/r/20230906132735.748174-1-valentin.caron@foss.st.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi-stm32.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c index 7ddf9db776b06..4737a36e5d4e9 100644 --- a/drivers/spi/spi-stm32.c +++ b/drivers/spi/spi-stm32.c @@ -275,6 +275,7 @@ struct stm32_spi_cfg { * @fifo_size: size of the embedded fifo in bytes * @cur_midi: master inter-data idleness in ns * @cur_speed: speed configured in Hz + * @cur_half_period: time of a half bit in us * @cur_bpw: number of bits in a single SPI data frame * @cur_fthlv: fifo threshold level (data frames in a single data packet) * @cur_comm: SPI communication mode @@ -302,6 +303,7 @@ struct stm32_spi {
unsigned int cur_midi; unsigned int cur_speed; + unsigned int cur_half_period; unsigned int cur_bpw; unsigned int cur_fthlv; unsigned int cur_comm; @@ -466,6 +468,8 @@ static int stm32_spi_prepare_mbr(struct stm32_spi *spi, u32 speed_hz,
spi->cur_speed = spi->clk_rate / (1 << mbrdiv);
+ spi->cur_half_period = DIV_ROUND_CLOSEST(USEC_PER_SEC, 2 * spi->cur_speed); + return mbrdiv - 1; }
@@ -707,6 +711,10 @@ static void stm32h7_spi_disable(struct stm32_spi *spi) return; }
+ /* Add a delay to make sure that transmission is ended. */ + if (spi->cur_half_period) + udelay(spi->cur_half_period); + if (spi->cur_usedma && spi->dma_tx) dmaengine_terminate_async(spi->dma_tx); if (spi->cur_usedma && spi->dma_rx)