Re: [PATCH] arm64: dts: realtek: Add Realtek rtd1619 and mjolnir

From: "Andreas Färber" <afaerber@suse.de>
To: James Tai <james.tai@realtek.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
	Rob Herring <robh+dt@kernel.org>,
	"'linux-kernel@vger.kernel.org'" <linux-kernel@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	"linux-realtek-soc@lists.infradead.org"
	<linux-realtek-soc@lists.infradead.org>
Subject: Re: [PATCH] arm64: dts: realtek: Add Realtek rtd1619 and mjolnir
Date: Tue, 19 Nov 2019 10:11:39 +0100	[thread overview]
Message-ID: <6182b89f-cd7e-ce7c-56f7-e2f500321cde@suse.de> (raw)
In-Reply-To: <43B123F21A8CFE44A9641C099E4196FFCF920024@RTITMBSVM04.realtek.com.tw>

Hi James,

Am 08.11.19 um 16:36 schrieb James Tai:
>> Is the UART no longer behind an IRQ mux on RTD1619, or is the above the IRQ
>> mux interrupt as a workaround for lack of in-tree irqchip driver?
>>
> Yes, the UART no longer behind an IRQ mux on RTD1619.

This conflicts with what I see in BSP irq mux code here:
https://github.com/BPI-SINOVOIP/BPI-M4-bsp/blob/master/linux-rtk/drivers/irqchip/irq-rtd16xx.h

That does show UR0 as bit 2 for the iso irq mux, as for previous SoCs.
Is that code wrong, or does the same UART0 IP block have two alternative
interrupts for backwards compatibility? I therefore held back RTD1619
irq mux patches from my irqchip v4 series [1].

The BSP DT does assign non-mux interrupts to the UART node like you did:
https://github.com/BPI-SINOVOIP/BPI-M4-bsp/blob/master/linux-rtk/arch/arm64/boot/dts/realtek/rtd16xx/rtd-16xx.dtsi
And I obviously trust that you tested your DT to produce serial output.

Also note how there are UR1_TO and UR2_TO (TO = timeout?) in addition to
regular UR1 and UR2 interrupts in the mux above, just as for RTD1295 and
RTD1195 (UR1/UR1_TO only). From my irqmux v4 series posted last night I
had to drop those additional interrupts property values from the DT [2],
as they violate mainline's DesignWare DT schema's maxItems 1 and would
require a new compatible string (and a driver patch to make use of it).

https://github.com/BPI-SINOVOIP/BPI-M4-bsp/blob/master/linux-rtk/drivers/irqchip/irq-rtd119x.h
https://github.com/BPI-SINOVOIP/BPI-M4-bsp/blob/master/linux-rtk/drivers/irqchip/irq-rtd129x.h
https://github.com/BPI-SINOVOIP/BPI-M4-bsp/blob/master/linux-rtk/drivers/irqchip/irq-rtd139x.h

Regards,
Andreas

[1] https://patchwork.kernel.org/cover/11250643/
[2] https://patchwork.kernel.org/patch/11250645/

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