[PATCH 6.12 106/113] spi: tegra210-quad: Return IRQ_HANDLED when timeout already processed transfer

Greg Kroah-Hartman
2026-02-09T14:41:39Z

From: Breno Leitao <leitao@debian.org>

[ Upstream commit aabd8ea0aa253d40cf5f20a609fc3d6f61e38299 ]

When the ISR thread wakes up late and finds that the timeout handler
has already processed the transfer (curr_xfer is NULL), return
IRQ_HANDLED instead of IRQ_NONE.

Use a similar approach to tegra_qspi_handle_timeout() by reading
QSPI_TRANS_STATUS and checking the QSPI_RDY bit to determine if the
hardware actually completed the transfer. If QSPI_RDY is set, the
interrupt was legitimate and triggered by real hardware activity.
The fact that the timeout path handled it first doesn't make it
spurious. Returning IRQ_NONE incorrectly suggests the interrupt
wasn't for this device, which can cause issues with shared interrupt
lines and interrupt accounting.

Fixes: b4e002d8a7ce ("spi: tegra210-quad: Fix timeout handling")
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260126-tegra_xfer-v2-1-6d2115e4f387@debian.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/spi/spi-tegra210-quad.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-tegra210-quad.c b/drivers/spi/spi-tegra210-quad.c
index 39aa0f1485686..24f92af780188 100644
--- a/drivers/spi/spi-tegra210-quad.c
+++ b/drivers/spi/spi-tegra210-quad.c
@@ -1444,15 +1444,30 @@ static irqreturn_t handle_dma_based_xfer(struct tegra_qspi *tqspi)
static irqreturn_t tegra_qspi_isr_thread(int irq, void *context_data)
{
struct tegra_qspi *tqspi = context_data;
+ u32 status;
+
+ /*
+ * Read transfer status to check if interrupt was triggered by transfer
+ * completion
+ */
+ status = tegra_qspi_readl(tqspi, QSPI_TRANS_STATUS);

/*
* Occasionally the IRQ thread takes a long time to wake up (usually
* when the CPU that it's running on is excessively busy) and we have
* already reached the timeout before and cleaned up the timed out
* transfer. Avoid any processing in that case and bail out early.
+ *
+ * If no transfer is in progress, check if this was a real interrupt
+ * that the timeout handler already processed, or a spurious one.
*/
- if (!tqspi->curr_xfer)
- return IRQ_NONE;
+ if (!tqspi->curr_xfer) {
+ /* Spurious interrupt - transfer not ready */
+ if (!(status & QSPI_RDY))
+ return IRQ_NONE;
+ /* Real interrupt, already handled by timeout path */
+ return IRQ_HANDLED;
+ }

tqspi->status_reg = tegra_qspi_readl(tqspi, QSPI_FIFO_STATUS);

--
2.51.0