Re: [PATCH V7] irqchip/sifive-plic: Fixup EOI failed when masked

[Aurelien Jarno]

On 2021-11-05 17:47, guoren@xxxxxxxxxx wrote:
> From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
> 
> When using "devm_request_threaded_irq(,,,,IRQF_ONESHOT,,)" in the driver,
> only the first interrupt could be handled, and continue irq is blocked by
> hw. Because the riscv plic couldn't complete masked irq source which has
> been disabled in enable register. The bug was firstly reported in [1].
> 
> Here is the description of Interrupt Completion in PLIC spec [2]:
> 
> The PLIC signals it has completed executing an interrupt handler by
> writing the interrupt ID it received from the claim to the claim/complete
> register. The PLIC does not check whether the completion ID is the same
> as the last claim ID for that target. If the completion ID does not match
> an interrupt source that is currently enabled for the target, the
>                          ^^ ^^^^^^^^^ ^^^^^^^
> completion is silently ignored.
> 
> [1] http://lists.infradead.org/pipermail/linux-riscv/2021-July/007441.html
> [2] https://github.com/riscv/riscv-plic-spec/blob/8bc15a35d07c9edf7b5d23fec9728302595ffc4d/riscv-plic.adoc
> 
> Fixes: bb0fed1c60cc ("irqchip/sifive-plic: Switch to fasteoi flow")
> Reported-by: Vincent Pelletier <plr.vincent@xxxxxxxxx>
> Tested-by: Nikita Shubin <nikita.shubin@xxxxxxxxxxx>
> Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Anup Patel <anup@xxxxxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Marc Zyngier <maz@xxxxxxxxxx>
> Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
> Cc: Atish Patra <atish.patra@xxxxxxx>
> Cc: Nikita Shubin <nikita.shubin@xxxxxxxxxxx>
> Cc: incent Pelletier <plr.vincent@xxxxxxxxx>

Thanks for this patch. From what I understand, it fixes among other
things the possibility to read the DA9063 RTC more than once.

Does it means that we could now enable it in the device tree? I mean
something like the following patch that unfortunately I can't test now:

diff --git a/arch/riscv/boot/dts/sifive/hifive-unmatched-a00.dts b/arch/riscv/boot/dts/sifive/hifive-unmatched-a00.dts
index 2e4ea84f27e7..c357b48582f7 100644
--- a/arch/riscv/boot/dts/sifive/hifive-unmatched-a00.dts
+++ b/arch/riscv/boot/dts/sifive/hifive-unmatched-a00.dts
@@ -70,6 +70,10 @@ pmic@58 {
 		interrupts = <1 IRQ_TYPE_LEVEL_LOW>;
 		interrupt-controller;
 
+		onkey {
+			compatible = "dlg,da9063-onkey";
+		};
+
 		regulators {
 			vdd_bcore1: bcore1 {
 				regulator-min-microvolt = <900000>;
@@ -205,6 +209,14 @@ vdd_ldo11: ldo11 {
 				regulator-always-on;
 			};
 		};
+
+		rtc {
+			compatible = "dlg,da9063-rtc";
+		};
+
+		wdt {
+			compatible = "dlg,da9063-watchdog";
+		};
 	};
 };

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@xxxxxxxxxxx                 http://www.aurel32.net