Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Alain Volmat <alain.volmat@foss.st.com>
To:     <broonie@kernel.org>, <amelie.delaunay@foss.st.com>
CC:     <mcoquelin.stm32@gmail.com>, <alexandre.torgue@foss.st.com>,
        <linux-spi@vger.kernel.org>,
        <linux-stm32@st-md-mailman.stormreply.com>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <fabrice.gasnier@foss.st.com>,
        <alain.volmat@foss.st.com>
Subject: [PATCH 8/8] spi: stm32: make spurious and overrun interrupts visible
Date:   Fri, 5 Feb 2021 12:09:02 +0100
Message-ID: <1612523342-10466-9-git-send-email-alain.volmat@foss.st.com>
In-Reply-To: <1612523342-10466-1-git-send-email-alain.volmat@foss.st.com>
References: <1612523342-10466-1-git-send-email-alain.volmat@foss.st.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

We do not expect to receive spurious interrupts so rise a warning
if it happens.

RX overrun is an error condition that signals a corrupted RX
stream both in dma and in irq modes. Report the error and
abort the transfer in either cases.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
---
 drivers/spi/spi-stm32.c | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index 7692e2778df5..e7699758c609 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -895,8 +895,8 @@ static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id)
 		mask |= STM32H7_SPI_SR_RXP;
 
 	if (!(sr & mask)) {
-		dev_dbg(spi->dev, "spurious IT (sr=0x%08x, ier=0x%08x)\n",
-			sr, ier);
+		dev_warn(spi->dev, "spurious IT (sr=0x%08x, ier=0x%08x)\n",
+			 sr, ier);
 		spin_unlock_irqrestore(&spi->lock, flags);
 		return IRQ_NONE;
 	}
@@ -923,15 +923,8 @@ static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id)
 	}
 
 	if (sr & STM32H7_SPI_SR_OVR) {
-		dev_warn(spi->dev, "Overrun: received value discarded\n");
-		if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
-			stm32h7_spi_read_rxfifo(spi, false);
-		/*
-		 * If overrun is detected while using DMA, it means that
-		 * something went wrong, so stop the current transfer
-		 */
-		if (spi->cur_usedma)
-			end = true;
+		dev_err(spi->dev, "Overrun: RX data lost\n");
+		end = true;
 	}
 
 	if (sr & STM32H7_SPI_SR_EOT) {
-- 
2.17.1