Re: Re: [PATCH v6 11/13] serial: 8250_dw: add Ambarella CV75 quirks

On Thu, Sep 10, 2026 at 05:12:52PM +0800, zl020895 wrote:

quoted

Wondering if we should undo this in the port's .shutdown() callback.

I saw the shutdown path already covers it: dw8250_shutdown() calls
serial8250_do_shutdown(), which does
	up->ier = 0;
	serial_port_out(port, UART_IER, 0);
so both the IER shadow and hardware IER are cleared, including ETOI.

Depending on the answer to Ilpo the enabling may need an updated comment
summarising the above.

At 2026-09-10 16:33:14, "Andy Shevchenko" [off-list ref] wrote:

quoted

On Fri, Sep 04, 2026 at 02:38:18PM +0800, Long Zhao via B4 Relay wrote:

...

quoted

quoted

+	/*
+	 * Ambarella keeps variant IER bits (e.g. ETOI) set for correct RX
+	 * timeout behaviour. Force them into the 8250 IER shadow so later
+	 * generic IER updates do not clear them.
+	 */

Wondering if we should undo this in the port's .shutdown() callback.

-- 
With Best Regards,
Andy Shevchenko