diff options
Diffstat (limited to 'target/linux/bcm27xx/patches-5.4/950-0863-irqchip-bcm2835-Quiesce-IRQs-left-enabled-by-bootloa.patch')
| -rw-r--r-- | target/linux/bcm27xx/patches-5.4/950-0863-irqchip-bcm2835-Quiesce-IRQs-left-enabled-by-bootloa.patch | 105 |
1 files changed, 0 insertions, 105 deletions
diff --git a/target/linux/bcm27xx/patches-5.4/950-0863-irqchip-bcm2835-Quiesce-IRQs-left-enabled-by-bootloa.patch b/target/linux/bcm27xx/patches-5.4/950-0863-irqchip-bcm2835-Quiesce-IRQs-left-enabled-by-bootloa.patch deleted file mode 100644 index f27d448864..0000000000 --- a/target/linux/bcm27xx/patches-5.4/950-0863-irqchip-bcm2835-Quiesce-IRQs-left-enabled-by-bootloa.patch +++ /dev/null @@ -1,105 +0,0 @@ -From 4ae861da5eaf53e5b4303f080bff0e34e22da0d9 Mon Sep 17 00:00:00 2001 -From: Lukas Wunner <lukas@wunner.de> -Date: Tue, 4 Feb 2020 15:50:41 +0100 -Subject: [PATCH] irqchip/bcm2835: Quiesce IRQs left enabled by - bootloader - -[ Upstream commit bd59b343a9c902c522f006e6d71080f4893bbf42 ] - -Per the spec, the BCM2835's IRQs are all disabled when coming out of -power-on reset. Its IRQ driver assumes that's still the case when the -kernel boots and does not perform any initialization of the registers. -However the Raspberry Pi Foundation's bootloader leaves the USB -interrupt enabled when handing over control to the kernel. - -Quiesce IRQs and the FIQ if they were left enabled and log a message to -let users know that they should update the bootloader once a fixed -version is released. - -If the USB interrupt is not quiesced and the USB driver later on claims -the FIQ (as it does on the Raspberry Pi Foundation's downstream kernel), -interrupt latency for all other peripherals increases and occasional -lockups occur. That's because both the FIQ and the normal USB interrupt -fire simultaneously: - -On a multicore Raspberry Pi, if normal interrupts are routed to CPU 0 -and the FIQ to CPU 1 (hardcoded in the Foundation's kernel), then a USB -interrupt causes CPU 0 to spin in bcm2836_chained_handle_irq() until the -FIQ on CPU 1 has cleared it. Other peripherals' interrupts are starved -as long. I've seen CPU 0 blocked for up to 2.9 msec. eMMC throughput -on a Compute Module 3 irregularly dips to 23.0 MB/s without this commit -but remains relatively constant at 23.5 MB/s with 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. At best users get RCU CPU stall warnings, but most -of the time the system just freezes. - -Fixes: 89214f009c1d ("ARM: bcm2835: add interrupt controller driver") -Signed-off-by: Lukas Wunner <lukas@wunner.de> -Signed-off-by: Marc Zyngier <maz@kernel.org> -Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> -Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> -Link: https://lore.kernel.org/r/f97868ba4e9b86ddad71f44ec9d8b3b7d8daa1ea.1582618537.git.lukas@wunner.de ---- - drivers/irqchip/irq-bcm2835.c | 21 +++++++++++++++++---- - 1 file changed, 17 insertions(+), 4 deletions(-) - ---- a/drivers/irqchip/irq-bcm2835.c -+++ b/drivers/irqchip/irq-bcm2835.c -@@ -67,8 +67,7 @@ - #define ARM_LOCAL_GPU_INT_ROUTING 0x0c - - #define REG_FIQ_CONTROL 0x0c --#define REG_FIQ_ENABLE 0x80 --#define REG_FIQ_DISABLE 0 -+#define FIQ_CONTROL_ENABLE BIT(7) - - #define NR_BANKS 3 - #define IRQS_PER_BANK 32 -@@ -116,7 +115,7 @@ static inline unsigned int hwirq_to_fiq( - static void armctrl_mask_irq(struct irq_data *d) - { - if (d->hwirq >= NUMBER_IRQS) -- writel_relaxed(REG_FIQ_DISABLE, intc.base + REG_FIQ_CONTROL); -+ writel_relaxed(0, intc.base + REG_FIQ_CONTROL); - else - writel_relaxed(HWIRQ_BIT(d->hwirq), - intc.disable[HWIRQ_BANK(d->hwirq)]); -@@ -143,7 +142,7 @@ static void armctrl_unmask_irq(struct ir - ARM_LOCAL_GPU_INT_ROUTING); - } - -- writel_relaxed(REG_FIQ_ENABLE | hwirq_to_fiq(d->hwirq), -+ writel_relaxed(FIQ_CONTROL_ENABLE | hwirq_to_fiq(d->hwirq), - intc.base + REG_FIQ_CONTROL); - } else { - writel_relaxed(HWIRQ_BIT(d->hwirq), -@@ -201,6 +200,7 @@ static int __init armctrl_of_init(struct - { - void __iomem *base; - int irq = 0, last_irq, b, i; -+ u32 reg; - - base = of_iomap(node, 0); - if (!base) -@@ -224,6 +224,19 @@ static int __init armctrl_of_init(struct - 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 & FIQ_CONTROL_ENABLE) { -+ writel_relaxed(0, base + REG_FIQ_CONTROL); -+ pr_err(FW_BUG "Bootloader left fiq enabled\n"); - } - - last_irq = irq; |