virt inclusion category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9391 -------------------------------------------------------------------- If hundreds of virtual machines all have virtio devices and are repeatedly restarted, a large number of MAPD (v=0) entries will be generated in batches. In this scenario, it is possible that the DT cache cannot be cleared even after 100 attempts. The time required to clear the cache once is approximately 100 nanoseconds. Based on a timeout period of 1 second, we set the number of timeout attempts to 1,000,000. Signed-off-by: Jinqian Yang <yangjinqian1@huawei.com> --- drivers/irqchip/irq-gic-v3-its.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 2a79ee777571..dbceebb97ed4 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -1044,7 +1044,7 @@ static struct its_collection u32 *dt_entry; void __iomem *its_func_en = its->sgir_base + 0x80; u32 tmp, tmp1, mask = 1 << 19; - int i = 100; + int i = 1000000; /* * The device table is flat. Modify v to 0 in the dt entry of devid, @@ -1062,6 +1062,9 @@ static struct its_collection * (offset is 0x20000), so address of GITS_FUNC_EN can be got by * sgir_base + 0x80. Bit 16 is used to clear DT cache, the flip of * bit 19 indicates that DT cache has been cleared. + * + * The time for each loop operation is approximately 100ns to 500ns, + * and the ITS should clear the DT cache within 1,000,000 loops. */ while (--i) { tmp = readl_relaxed(its_func_en) & mask; -- 2.33.0