spi: tegra210-quad: Move curr_xfer read inside spinlock

[ Upstream commit ef13ba357656451d6371940d8414e3e271df97e3 ]

Move the assignment of the transfer pointer from curr_xfer inside the
spinlock critical section in both handle_cpu_based_xfer() and
handle_dma_based_xfer().

Previously, curr_xfer was read before acquiring the lock, creating a
window where the timeout path could clear curr_xfer between reading it
and using it. By moving the read inside the lock, the handlers are
guaranteed to see a consistent value that cannot be modified by the
timeout path.

Fixes: 921fc1838fb0 ("spi: tegra210-quad: Add support for Tegra210 QSPI controller")
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://patch.msgid.link/20260126-tegra_xfer-v2-2-6d2115e4f387@debian.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/spi/spi-tegra210-quad.c b/drivers/spi/spi-tegra210-quad.c
index c6c05e6f48994e06f6ec6ec6c5bd43230d8606f4..a599bad02b4d39797f5f428ba04d8d31972018e3 100644 (file)
--- a/drivers/spi/spi-tegra210-quad.c
+++ b/drivers/spi/spi-tegra210-quad.c
@@ -1376,10 +1376,11 @@ static int tegra_qspi_transfer_one_message(struct spi_controller *host,
 
 static irqreturn_t handle_cpu_based_xfer(struct tegra_qspi *tqspi)
 {
-       struct spi_transfer *t = tqspi->curr_xfer;
+       struct spi_transfer *t;
        unsigned long flags;
 
        spin_lock_irqsave(&tqspi->lock, flags);
+       t = tqspi->curr_xfer;
 
        if (tqspi->tx_status ||  tqspi->rx_status) {
                tegra_qspi_handle_error(tqspi);
@@ -1410,7 +1411,7 @@ exit:
 
 static irqreturn_t handle_dma_based_xfer(struct tegra_qspi *tqspi)
 {
-       struct spi_transfer *t = tqspi->curr_xfer;
+       struct spi_transfer *t;
        unsigned int total_fifo_words;
        unsigned long flags;
        long wait_status;
@@ -1449,6 +1450,7 @@ static irqreturn_t handle_dma_based_xfer(struct tegra_qspi *tqspi)
        }
 
        spin_lock_irqsave(&tqspi->lock, flags);
+       t = tqspi->curr_xfer;
 
        if (num_errors) {
                tegra_qspi_dma_unmap_xfer(tqspi, t);