Re: [PATCH v3 3/3] spi: tegra210-quad: Process small PIO transfers in hard IRQ context

[Mark Brown]

On Wed, May 20, 2026 at 07:24:05PM +0000, Vishwaroop A wrote:

> The 256-byte threshold (FIFO depth) ensures small transfers for devices
> like TPMs use the fast path, while larger transfers continue using
> workqueue.

> +	/*
> +	 * For small PIO transfers (e.g., TPM), process directly in hard IRQ
> +	 * context unless there was a FIFO error. Error recovery calls
> +	 * device_reset() which can sleep, so must be deferred to workqueue.
> +	 */
> +	if (!tqspi->is_curr_dma_xfer && tqspi->curr_dma_words <= QSPI_FIFO_DEPTH &&
> +	    !tqspi->tx_status && !tqspi->rx_status)
> +		return handle_cpu_based_xfer(tqspi);

Is cur_dma_words always in the same units as QSPI_FIFO_DEPTH - I see
there's packed transfer support in the driver?

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