Re: [PATCH v6 10/10] dmaengine: dw: Prevent tx-status calling DMA-desc callback

[sashiko-bot@kernel.org]

> From: Serge Semin <fancer.lancer@gmail.com>
> 
> The DMA transfer status getter can invoke a completion callback from
> dwc_scan_descriptors(). An 8250 RX timeout queries that status while
> holding the UART port lock, and its DMA callback takes the same lock:
> 
>   serial8250_handle_irq()
>     uart_port_lock_irqsave(port)
>     serial8250_rx_dma_flush()
>       dmaengine_tx_status()
>         dwc_scan_descriptors()
>           dwc_descriptor_free()
>             dma_rx_complete()
>               uart_port_lock_irqsave(port)
> 
> [ ... ]
> Fixes: 3bfb1d20b547 ("dmaengine: Driver for the Synopsys DesignWare DMA controller")
> Cc: stable@vger.kernel.org
> Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
> [james: defer notifications while preserving polled completion and cleanup]
> Signed-off-by: James Hilliard <james.hilliard1@gmail.com>

Sashiko has reviewed this patch and found no issues.

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Sashiko AI review · https://sashiko.dev/#/patchset/20261103-submit-dw-dma-synchronize-v1-v6-0-2ee0c348224d@gmail.com?part=10