[PATCH] spi: tegra210-quad: Fix false positive WARN on interrupt timeout with transfer complete

[PATCH] spi: tegra210-quad: Fix false positive WARN on interrupt timeout with transfer complete

[Breno Leitao]

The WARN_ON_ONCE/WARN_ON fired unconditionally on any completion
timeout, including the recoverable case where the interrupt was lost but
the hardware actually finished the transfer. This produced a noisy splat
with a full call trace even though the driver successfully recovered via
tegra_qspi_handle_timeout().

Since tegra210 uses threaded interrupts, the transfer completion can be
signaled before the interrupt fires, making this false positive case
common in practice.

Almost all the hosts I sysadmin in my fleet produce the following splat:

	WARNING: CPU: 47 PID: 844 at drivers/spi/spi-tegra210-quad.c:1226 tegra_qspi_transfer_one_message+0x8a4/0xba8
	....
	tegra-qspi NVDA1513:00: QSPI interrupt timeout, but transfer complete

Move WARN_ON_ONCE/WARN_ON to fire only on real unrecoverable timeouts,
i.e., when tegra_qspi_handle_timeout() confirms the hardware did NOT
complete. This makes the warning actionable instead of just polluting
the metrics.

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 drivers/spi/spi-tegra210-quad.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-tegra210-quad.c b/drivers/spi/spi-tegra210-quad.c
index 7cca5578eba31..db28dd556484b 100644
--- a/drivers/spi/spi-tegra210-quad.c
+++ b/drivers/spi/spi-tegra210-quad.c
@@ -1223,7 +1223,7 @@ static int tegra_qspi_combined_seq_xfer(struct tegra_qspi *tqspi,
 					(&tqspi->xfer_completion,
 					QSPI_DMA_TIMEOUT);
 
-			if (WARN_ON_ONCE(ret == 0)) {
+			if (ret == 0) {
 				/*
 				 * Check if hardware completed the transfer
 				 * even though interrupt was lost or delayed.
@@ -1232,6 +1232,7 @@ static int tegra_qspi_combined_seq_xfer(struct tegra_qspi *tqspi,
 				ret = tegra_qspi_handle_timeout(tqspi);
 				if (ret < 0) {
 					/* Real timeout - clean up and fail */
+					WARN_ON_ONCE(1);
 					dev_err(tqspi->dev, "transfer timeout\n");
 
 					/* Abort transfer by resetting pio/dma bit */
@@ -1340,7 +1341,7 @@ static int tegra_qspi_non_combined_seq_xfer(struct tegra_qspi *tqspi,
 
 		ret = wait_for_completion_timeout(&tqspi->xfer_completion,
 						  QSPI_DMA_TIMEOUT);
-		if (WARN_ON(ret == 0)) {
+		if (ret == 0) {
 			/*
 			 * Check if hardware completed the transfer even though
 			 * interrupt was lost or delayed. If so, process the
@@ -1349,6 +1350,7 @@ static int tegra_qspi_non_combined_seq_xfer(struct tegra_qspi *tqspi,
 			ret = tegra_qspi_handle_timeout(tqspi);
 			if (ret < 0) {
 				/* Real timeout - clean up and fail */
+				WARN_ON(1);
 				dev_err(tqspi->dev, "transfer timeout\n");
 
 				if (tqspi->is_curr_dma_xfer)

---
base-commit: f3e6330d7fe42b204af05a2dbc68b379e0ad179e
change-id: 20260408-tegra_warn-cecd2ca3a61b

Best regards,
--  
Breno Leitao <leitao@debian.org>

Re: [PATCH] spi: tegra210-quad: Fix false positive WARN on interrupt timeout with transfer complete

[Mark Brown]

On Wed, 08 Apr 2026 06:45:43 -0700, Breno Leitao wrote:
> spi: tegra210-quad: Fix false positive WARN on interrupt timeout with transfer complete

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-7.1

Thanks!

[1/1] spi: tegra210-quad: Fix false positive WARN on interrupt timeout with transfer complete
      https://git.kernel.org/broonie/spi/c/5b94c94caafc

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark