From d87a5d64b5037cfedd7eb47d785b5c159ace8d9b Mon Sep 17 00:00:00 2001 From: Amelie Delaunay Date: Wed, 7 Jul 2021 10:27:04 +0200 Subject: [PATCH] spi: stm32h7: rework rx fifo read function Remove flush parameter and check RXWNE or RXPLVL when end of transfer flag is set. Signed-off-by: Amelie Delaunay Signed-off-by: Alain Volmat Link: https://lore.kernel.org/r/1625646426-5826-6-git-send-email-alain.volmat@foss.st.com Signed-off-by: Mark Brown --- drivers/spi/spi-stm32.c | 30 +++++++++++++----------------- 1 file changed, 13 insertions(+), 17 deletions(-) diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c index d37bfea..c2144e3 100644 --- a/drivers/spi/spi-stm32.c +++ b/drivers/spi/spi-stm32.c @@ -570,29 +570,30 @@ static void stm32f4_spi_read_rx(struct stm32_spi *spi) /** * stm32h7_spi_read_rxfifo - Read bytes in Receive Data Register * @spi: pointer to the spi controller data structure - * @flush: boolean indicating that FIFO should be flushed * * Write in rx_buf depends on remaining bytes to avoid to write beyond * rx_buf end. */ -static void stm32h7_spi_read_rxfifo(struct stm32_spi *spi, bool flush) +static void stm32h7_spi_read_rxfifo(struct stm32_spi *spi) { u32 sr = readl_relaxed(spi->base + STM32H7_SPI_SR); u32 rxplvl = FIELD_GET(STM32H7_SPI_SR_RXPLVL, sr); while ((spi->rx_len > 0) && ((sr & STM32H7_SPI_SR_RXP) || - (flush && ((sr & STM32H7_SPI_SR_RXWNE) || (rxplvl > 0))))) { + ((sr & STM32H7_SPI_SR_EOT) && + ((sr & STM32H7_SPI_SR_RXWNE) || (rxplvl > 0))))) { u32 offs = spi->cur_xferlen - spi->rx_len; if ((spi->rx_len >= sizeof(u32)) || - (flush && (sr & STM32H7_SPI_SR_RXWNE))) { + (sr & STM32H7_SPI_SR_RXWNE)) { u32 *rx_buf32 = (u32 *)(spi->rx_buf + offs); *rx_buf32 = readl_relaxed(spi->base + STM32H7_SPI_RXDR); spi->rx_len -= sizeof(u32); } else if ((spi->rx_len >= sizeof(u16)) || - (flush && (rxplvl >= 2 || spi->cur_bpw > 8))) { + (!(sr & STM32H7_SPI_SR_RXWNE) && + (rxplvl >= 2 || spi->cur_bpw > 8))) { u16 *rx_buf16 = (u16 *)(spi->rx_buf + offs); *rx_buf16 = readw_relaxed(spi->base + STM32H7_SPI_RXDR); @@ -608,8 +609,8 @@ static void stm32h7_spi_read_rxfifo(struct stm32_spi *spi, bool flush) rxplvl = FIELD_GET(STM32H7_SPI_SR_RXPLVL, sr); } - dev_dbg(spi->dev, "%s%s: %d bytes left\n", __func__, - flush ? "(flush)" : "", spi->rx_len); + dev_dbg(spi->dev, "%s: %d bytes left (sr=%08x)\n", + __func__, spi->rx_len, sr); } /** @@ -677,12 +678,7 @@ static void stm32f4_spi_disable(struct stm32_spi *spi) * @spi: pointer to the spi controller data structure * * RX-Fifo is flushed when SPI controller is disabled. To prevent any data - * loss, use stm32h7_spi_read_rxfifo(flush) to read the remaining bytes in - * RX-Fifo. - * Normally, if TSIZE has been configured, we should relax the hardware at the - * reception of the EOT interrupt. But in case of error, EOT will not be - * raised. So the subsystem unprepare_message call allows us to properly - * complete the transfer from an hardware point of view. + * loss, use stm32_spi_read_rxfifo to read the remaining bytes in RX-Fifo. */ static void stm32h7_spi_disable(struct stm32_spi *spi) { @@ -717,7 +713,7 @@ static void stm32h7_spi_disable(struct stm32_spi *spi) } if (!spi->cur_usedma && spi->rx_buf && (spi->rx_len > 0)) - stm32h7_spi_read_rxfifo(spi, true); + stm32h7_spi_read_rxfifo(spi); if (spi->cur_usedma && spi->dma_tx) dmaengine_terminate_all(spi->dma_tx); @@ -913,7 +909,7 @@ static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id) if (__ratelimit(&rs)) dev_dbg_ratelimited(spi->dev, "Communication suspended\n"); if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0))) - stm32h7_spi_read_rxfifo(spi, false); + stm32h7_spi_read_rxfifo(spi); /* * If communication is suspended while using DMA, it means * that something went wrong, so stop the current transfer @@ -934,7 +930,7 @@ static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id) if (sr & STM32H7_SPI_SR_EOT) { if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0))) - stm32h7_spi_read_rxfifo(spi, true); + stm32h7_spi_read_rxfifo(spi); end = true; } @@ -944,7 +940,7 @@ static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id) if (sr & STM32H7_SPI_SR_RXP) if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0))) - stm32h7_spi_read_rxfifo(spi, false); + stm32h7_spi_read_rxfifo(spi); writel_relaxed(sr & mask, spi->base + STM32H7_SPI_IFCR); -- 2.7.4