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From: Thomas Gleixner <tglx@kernel.org>
To: Stafford Horne <shorne@gmail.com>, LKML <linux-kernel@vger.kernel.org>
Cc: Linux OpenRISC <linux-openrisc@vger.kernel.org>,
	devicetree <devicetree@vger.kernel.org>,
	Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Stafford Horne <shorne@gmail.com>,
	Jonas Bonn <jonas@southpole.se>,
	Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Subject: Re: [PATCH v4 4/6] openrisc: Fix IPIs on simple multicore systems
Date: Tue, 13 Jan 2026 18:21:55 +0100	[thread overview]
Message-ID: <873449jumk.ffs@tglx> (raw)
In-Reply-To: <20260113161152.3688309-5-shorne@gmail.com>

On Tue, Jan 13 2026 at 16:11, Stafford Horne wrote:
> Commit c05671846451 ("openrisc: sleep instead of spin on secondary
> wait") fixed OpenRISC SMP Linux for QEMU. However, stability was never
> achieved on FPGA development boards.  This is because the above patch
> has a step to unmask IPIs on non-boot cpu's but on hardware without
> power management, IPIs remain masked.
>
> This meant that IPI's were never actually working on the simple SMP
> systems we run on development boards.  The systems booted but stability
> was very suspect.
>
> Add the ability to unmask IPI's on the non-boot cores.  This is done by
> making the OMPIC IRQs proper percpu IRQs.  We can then use the
> enabled_percpu_irq() to unmask IRQ on the non-boot cpus.
>
> Update the or1k PIC driver to use a flow handler that can switch between
> percpu and the configured level or edge flow handlers at runtime.
> This mechanism is inspired by that done in the J-Core AIC driver.
>
> Signed-off-by: Stafford Horne <shorne@gmail.com>

Acked-by: Thomas Gleixner <tglx@kernel.org>

  reply	other threads:[~2026-01-13 17:21 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-01-13 16:11 [PATCH v4 0/6] OpenRISC de0 nano single and multicore boards Stafford Horne
2026-01-13 16:11 ` [PATCH v4 1/6] dt-bindings: gpio-mmio: Add opencores GPIO Stafford Horne
2026-01-13 16:20   ` Bartosz Golaszewski
2026-01-13 16:31     ` Stafford Horne
2026-01-14  8:31       ` Krzysztof Kozlowski
2026-01-14  8:36         ` Bartosz Golaszewski
2026-01-14 14:24           ` Stafford Horne
2026-01-13 16:11 ` [PATCH v4 2/6] gpio: mmio: Add compatible for " Stafford Horne
2026-01-13 16:11 ` [PATCH v4 3/6] openrisc: dts: Add de0 nano config and devicetree Stafford Horne
2026-01-13 16:11 ` [PATCH v4 4/6] openrisc: Fix IPIs on simple multicore systems Stafford Horne
2026-01-13 17:21   ` Thomas Gleixner [this message]
2026-01-13 16:11 ` [PATCH v4 5/6] openrisc: dts: Split simple smp dts to dts and dtsi Stafford Horne
2026-01-13 16:11 ` [PATCH v4 6/6] openrisc: dts: Add de0 nano multicore config and devicetree Stafford Horne

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