diff options
Diffstat (limited to 'bcm2835-irqchip-Quiesce-IRQs-left-enabled-by-bootloader.patch')
| -rw-r--r-- | bcm2835-irqchip-Quiesce-IRQs-left-enabled-by-bootloader.patch | 232 |
1 files changed, 0 insertions, 232 deletions
diff --git a/bcm2835-irqchip-Quiesce-IRQs-left-enabled-by-bootloader.patch b/bcm2835-irqchip-Quiesce-IRQs-left-enabled-by-bootloader.patch deleted file mode 100644 index 9cb8ff5d7..000000000 --- a/bcm2835-irqchip-Quiesce-IRQs-left-enabled-by-bootloader.patch +++ /dev/null @@ -1,232 +0,0 @@ -From patchwork Mon Feb 10 09:52:20 2020 -Content-Type: text/plain; charset="utf-8" -MIME-Version: 1.0 -Content-Transfer-Encoding: 7bit -X-Patchwork-Submitter: Lukas Wunner <lukas@wunner.de> -X-Patchwork-Id: 11372935 -Return-Path: - <SRS0=uiPw=36=lists.infradead.org=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@kernel.org> -Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org - [172.30.200.123]) - by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6E6F4109A - for <patchwork-linux-arm@patchwork.kernel.org>; - Mon, 10 Feb 2020 09:52:52 +0000 (UTC) -Received: from bombadil.infradead.org (bombadil.infradead.org - [198.137.202.133]) - (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) - (No client certificate requested) - by mail.kernel.org (Postfix) with ESMTPS id 3ABD621835 - for <patchwork-linux-arm@patchwork.kernel.org>; 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- Mon, 10 Feb 2020 10:52:31 +0100 (CET) -Received: from localhost (unknown [87.130.102.138]) - (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) - (No client certificate requested) - by h08.hostsharing.net (Postfix) with ESMTPSA id E85DF60AD5E1; - Mon, 10 Feb 2020 10:52:30 +0100 (CET) -X-Mailbox-Line: From 8be2f3e95fb29abdf80240f2b8a38621c42eb2a9 Mon Sep 17 - 00:00:00 2001 -Message-Id: - <8be2f3e95fb29abdf80240f2b8a38621c42eb2a9.1581327911.git.lukas@wunner.de> -In-Reply-To: <713627a200d9c8fd7cac424d69e98166@kernel.org> -References: <713627a200d9c8fd7cac424d69e98166@kernel.org> -From: Lukas Wunner <lukas@wunner.de> -Date: Mon, 10 Feb 2020 10:52:20 +0100 -Subject: [PATCH v2] irqchip/bcm2835: Quiesce IRQs left enabled by bootloader -To: Thomas Gleixner <tglx@linutronix.de>, Jason Cooper <jason@lakedaemon.net>, - Marc Zyngier <maz@kernel.org>, - "Nicolas Saenz Julienne" <nsaenzjulienne@suse.de> -X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 -X-CRM114-CacheID: sfid-20200210_015244_903439_EE700514 -X-CRM114-Status: GOOD ( 18.64 ) -X-Spam-Score: -0.7 (/) -X-Spam-Report: SpamAssassin version 3.4.3 on bombadil.infradead.org summary: - Content analysis details: (-0.7 points) - pts rule name description - ---- ---------------------- - -------------------------------------------------- - -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at https://www.dnswl.org/, - low trust [83.223.95.204 listed in list.dnswl.org] - 0.0 RCVD_IN_MSPIKE_H3 RBL: Good reputation (+3) - [83.223.95.204 listed in wl.mailspike.net] - 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record - 0.0 SPF_NONE SPF: sender does not publish an SPF Record - 0.0 RCVD_IN_MSPIKE_WL Mailspike good senders -X-BeenThere: linux-arm-kernel@lists.infradead.org -X-Mailman-Version: 2.1.29 -Precedence: list -List-Id: <linux-arm-kernel.lists.infradead.org> -List-Unsubscribe: - <http://lists.infradead.org/mailman/options/linux-arm-kernel>, - <mailto:linux-arm-kernel-request@lists.infradead.org?subject=unsubscribe> -List-Archive: <http://lists.infradead.org/pipermail/linux-arm-kernel/> -List-Post: <mailto:linux-arm-kernel@lists.infradead.org> -List-Help: <mailto:linux-arm-kernel-request@lists.infradead.org?subject=help> -List-Subscribe: - <http://lists.infradead.org/mailman/listinfo/linux-arm-kernel>, - <mailto:linux-arm-kernel-request@lists.infradead.org?subject=subscribe> -Cc: Florian Fainelli <f.fainelli@gmail.com>, - Kristina Brooks <notstina@gmail.com>, Scott Branden <sbranden@broadcom.com>, - Ray Jui <rjui@broadcom.com>, Serge Schneider <serge@raspberrypi.org>, - linux-kernel@vger.kernel.org, Phil Elwell <phil@raspberrypi.org>, - Matthias Brugger <mbrugger@suse.com>, bcm-kernel-feedback-list@broadcom.com, - linux-rpi-kernel@lists.infradead.org, Martin Sperl <kernel@martin.sperl.org>, - linux-arm-kernel@lists.infradead.org, Stefan Wahren <wahrenst@gmx.net> -MIME-Version: 1.0 -Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> -Errors-To: - linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org - -Customers of our "Revolution Pi" open source PLCs (which are based on -the Raspberry Pi) have reported random lockups as well as jittery eMMC, -UART and SPI latency. We were able to reproduce the lockups in our lab -and hooked up a JTAG debugger: - -It turns out that the USB controller's interrupt is already enabled when -the kernel boots. All interrupts are disabled when the chip comes out -of power-on reset, according to the spec. So apparently the bootloader -enables the interrupt but neglects to disable it before handing over -control to the kernel. - -The bootloader is a closed source blob provided by the Raspberry Pi -Foundation. Development of an alternative open source bootloader was -begun by Kristina Brooks but it's not fully functional yet. Usage of -the blob is thus without alternative for the time being. - -The Raspberry Pi Foundation's downstream kernel has a performance- -optimized USB driver (which we use on our Revolution Pi products). -The driver takes advantage of the FIQ fast interrupt. Because the -regular USB interrupt was left enabled by the bootloader, both the -FIQ and the normal interrupt is enabled once the USB driver probes. - -The spec has the following to say on simultaneously enabling the FIQ -and the normal interrupt of a peripheral: - -"One interrupt source can be selected to be connected to the ARM FIQ - input. An interrupt which is selected as FIQ should have its normal - interrupt enable bit cleared. Otherwise a normal and an FIQ interrupt - will be fired at the same time. Not a good idea!" - ^^^^^^^^^^^^^^^ -https://www.raspberrypi.org/app/uploads/2012/02/BCM2835-ARM-Peripherals.pdf -page 110 - -On a multicore Raspberry Pi, the Foundation's kernel routes all normal -interrupts to CPU 0 and the FIQ to CPU 1. Because both the FIQ and the -normal interrupt is enabled, a USB interrupt causes CPU 0 to spin in -bcm2836_chained_handle_irq() until the FIQ on CPU 1 has cleared it. -Interrupts with a lower priority than USB are starved as long. - -That explains the jittery eMMC, UART and SPI latency: On one occasion -I've seen CPU 0 blocked for no less than 2.9 msec. Basically, -everything not USB takes a performance hit: Whereas eMMC throughput -on a Compute Module 3 remains relatively constant at 23.5 MB/s with -this commit, it irregularly dips to 23.0 MB/s without this commit. - -The lockups occur when CPU 0 receives a USB interrupt while holding a -lock which CPU 1 is trying to acquire while the FIQ is temporarily -disabled on CPU 1. - -I've tested old releases of the Foundation's bootloader as far back as -1.20160202-1 and they all leave the USB interrupt enabled. Still older -releases fail to boot a contemporary kernel on a Compute Module 1 or 3, -which are the only Raspberry Pi variants I have at my disposal for -testing. - -Fix by disabling IRQs left enabled by the bootloader. Although the -impact is most pronounced on the Foundation's downstream kernel, -it seems prudent to apply the fix to the upstream kernel to guard -against such mistakes in any present and future bootloader. - -Signed-off-by: Lukas Wunner <lukas@wunner.de> -Cc: Serge Schneider <serge@raspberrypi.org> -Cc: Kristina Brooks <notstina@gmail.com> -Cc: stable@vger.kernel.org -Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> ---- -Changes since v1: -* Use "relaxed" MMIO accessors to avoid memory barriers (Marc) -* Use u32 instead of int for register access (Marc) -* Quiesce FIQ as well (Marc) -* Quiesce IRQs after mapping them for better readability -* Drop alternative approach from commit message (Marc) - -Link to v1: -https://lore.kernel.org/lkml/988737dbbc4e499c2faaaa4e567ba3ed8deb9a89.1581089797.git.lukas@wunner.de/ - - drivers/irqchip/irq-bcm2835.c | 15 +++++++++++++++ - 1 file changed, 15 insertions(+) - -diff --git a/drivers/irqchip/irq-bcm2835.c b/drivers/irqchip/irq-bcm2835.c -index 418245d31921..63539c88ac3a 100644 ---- a/drivers/irqchip/irq-bcm2835.c -+++ b/drivers/irqchip/irq-bcm2835.c -@@ -61,6 +61,7 @@ - | SHORTCUT1_MASK | SHORTCUT2_MASK) - - #define REG_FIQ_CONTROL 0x0c -+#define REG_FIQ_ENABLE 0x80 - - #define NR_BANKS 3 - #define IRQS_PER_BANK 32 -@@ -135,6 +136,7 @@ static int __init armctrl_of_init(struct device_node *node, - { - void __iomem *base; - int irq, b, i; -+ u32 reg; - - base = of_iomap(node, 0); - if (!base) -@@ -157,6 +159,19 @@ static int __init armctrl_of_init(struct device_node *node, - handle_level_irq); - irq_set_probe(irq); - } -+ -+ reg = readl_relaxed(intc.enable[b]); -+ if (reg) { -+ writel_relaxed(reg, intc.disable[b]); -+ pr_err(FW_BUG "Bootloader left irq enabled: " -+ "bank %d irq %*pbl\n", b, IRQS_PER_BANK, ®); -+ } -+ } -+ -+ reg = readl_relaxed(base + REG_FIQ_CONTROL); -+ if (reg & REG_FIQ_ENABLE) { -+ writel_relaxed(0, base + REG_FIQ_CONTROL); -+ pr_err(FW_BUG "Bootloader left fiq enabled\n"); - } - - if (is_2836) { |