diff options
authorJames Hogan <james.hogan@imgtec.com>2017-08-12 21:36:09 -0700
committerRalf Baechle <ralf@linux-mips.org>2017-08-30 13:57:29 +0200
commit2c0e8382386f618c85d20cb05e7cf7df8cdd382c (patch)
parent5af2ed36697e2a48cd7d36232212caa6240fe9bb (diff)
irqchip: mips-gic: SYNC after enabling GIC region
A SYNC is required between enabling the GIC region and actually trying to use it, even if the first access is a read, otherwise its possible depending on the timing (and in my case depending on the precise alignment of certain kernel code) to hit CM bus errors on that first access. Add the SYNC straight after setting the GIC base. [paul.burton@imgtec.com: Changes later in this series increase our likelihood of hitting this by reducing the amount of code that runs between enabling the GIC & accessing it.] Fixes: a7057270c280 ("irqchip: mips-gic: Add device-tree support") Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Paul Burton <paul.burton@imgtec.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Cooper <jason@lakedaemon.net> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # 3.19.x- Patchwork: https://patchwork.linux-mips.org/patch/17019/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index 6ab1d3afec02..48ee1bad473f 100644
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -1020,8 +1020,11 @@ static int __init gic_of_init(struct device_node *node,
gic_len = resource_size(&res);
- if (mips_cm_present())
+ if (mips_cm_present()) {
write_gcr_gic_base(gic_base | CM_GCR_GIC_BASE_GICEN_MSK);
+ /* Ensure GIC region is enabled before trying to access it */
+ __sync();
+ }
gic_present = true;
__gic_init(gic_base, gic_len, cpu_vec, 0, node);