Message-ID: <sashiko-outbox-204388@kernel.org>
From: sashiko-bot@kernel.org
Subject: Re: [PATCH v10 4/8] serial: 8250_omap: quiesce DMA IRQ handling
 before shutdown
Reply-To: sashiko-reviews@lists.linux.dev
To: "James Hilliard" <james.hilliard1@gmail.com>
Cc: linux-serial@vger.kernel.org
In-Reply-To: <20261108-submit-serial-8250-dma-cancel-v1-v10-4-e6227ddb95b1@gmail.com>
References: <20261108-submit-serial-8250-dma-cancel-v1-v10-0-e6227ddb95b1@gmail.com>
 <20261108-submit-serial-8250-dma-cancel-v1-v10-4-e6227ddb95b1@gmail.com>
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Date: Mon, 09 Nov 2026 04:00:17 +0000
Precedence: list

> disable_irq_nosync() masks the UART interrupt without waiting for a
> running handler. That handler can have observed up->dma and continue
> using it while shutdown releases the DMA channels and clears the pointer.
> Synchronizing the IRQ later in serial core does not protect those accesse=
s.
>=20
> Publish the DMA shutdown gate under the port lock before the final RX
> flush and interrupt masking. Have DMA IRQ handling check the same gate
> under the lock, so a queued interrupt cannot restart receive processing
> after the final flush.
>=20
> Drain the UART IRQ outside the port lock before releasing DMA state.
> The lock excludes competing RX processing during the flush, while
> disable_irq() also waits for a handler that observed up->dma before
> acquiring the lock.
>=20
> Fixes: fef4f600319e ("serial: 8250: omap: Fix life cycle issues for inter=
rupt handlers")
> Reviewed-by: Raul E Rangel <rrangel@chromium.org>
> Signed-off-by: James Hilliard <james.hilliard1@gmail.com>

Sashiko has reviewed this patch and found no issues.

--=20
Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261108-submit-ser=
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