Re: [PATCH v5 0/3] spi: tegra210-quad: Improve timeout handling under high system load

[Jon Hunter]

On 28/10/2025 15:57, Vishwaroop A wrote:
> Hi,
>
> This patch series addresses timeout handling issues in the Tegra QSPI driver
> that occur under high system load conditions. We've observed that when CPUs
> are saturated (due to error injection, RAS firmware activity, or general CPU
> contention), QSPI interrupt handlers can be delayed, causing spurious transfer
> failures even though the hardware completed the operation successfully.
>
> Patch 1 fixes a stale pointer issue by ensuring curr_xfer is cleared on timeout
> and checked when the IRQ thread finally runs. It also ensures interrupts are
> properly cleared on failure paths.
>
> Patch 2 refactors the timeout cleanup code into dedicated helper functions
> (tegra_qspi_reset, tegra_qspi_dma_stop, tegra_qspi_pio_stop) to improve code
> readability and maintainability. This is purely a code reorganization with no
> functional changes.
>
> Patch 3 adds hardware status checking on timeout. Before failing a transfer,
> the driver now reads QSPI_TRANS_STATUS to verify if the hardware actually
> completed the operation. If so, it manually invokes the completion handler
> instead of failing the transfer. This distinguishes genuine hardware timeouts
> from delayed/lost interrupts.
>
> These changes have been tested in production environments under various high
> load scenarios including RAS testing and CPU saturation workloads.


For the series ...

Tested-by: Jon Hunter <jonathanh@xxxxxxxxxx>
Reviewed-by: Jon Hunter <jonathanh@xxxxxxxxxx>

Thanks
Jon

--
nvpublic