Hi Bjorn
Many thanks for your review.
It's in the Spring Festival holiday, so reply later.
On 2020/1/24 上午6:25, Bjorn Helgaas wrote:
On Thu, Jan 23, 2020 at 04:26:31PM +0800, Dongdong Liu wrote:
Current code do not call INIT_KFIFO() to init aer_fifo. This will lead to
kfifo_put() sometimes return 0. This means the fifo was full. In fact, it
is not.
It's definitely a problem that we don't call INIT_KFIFO(). But I'm
curious about why this would only be a problem "sometimes". The kfifo
is allocated with devm_kzalloc(), so it should be zero-filled and I
would think it would fail consistently, every time. But I guess not?
Yes, It would fail consistently, every time when it appeared once.
But when do echo 15 > /proc/sys/kernel/printk,
"aer_inject -s 82:00.0 multiple-corr-nonfatal" executes correctly.
I think this is related with the time when to call kfifo_put() and
kfifo_get().
case 1:
kfifo_put()--->kfifo_get()--->kfifo_put() //the fifo will not be full
case 2:
kfifo_put()--->kfifo_put()--->kfifo_get()
the fifo will be full when the second time to call kfifo_put();
It is easy to reproduce the problem by using aer_inject.
I assume maybe you mean "aer-inject" (not "aer_inject"), from
https://git.kernel.org/pub/scm/linux/kernel/git/gong.chen/aer-inject.git/ ?
At least, that's what's mentioned in Documentation/PCI/pcieaer-howto.rst.
Yes, you are right, I mean aer-inject.
Thanks,
Dongdong
aer_inject -s :82:00.0 multiple-corr-nonfatal
The content of multiple-corr-nonfatal file is as below.
AER
COR RCVR
HL 0 1 2 3
AER
UNCOR POISON_TLP
HL 4 5 6 7
Fixes: 27c1ce8bbed7 ("PCI/AER: Use kfifo for tracking events instead of reimplementing it")
Signed-off-by: Dongdong Liu <liudongdong3@xxxxxxxxxx>
---
drivers/pci/pcie/aer.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index 1ca86f2..4a818b0 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -1445,6 +1445,7 @@ static int aer_probe(struct pcie_device *dev)
return -ENOMEM;
rpc->rpd = port;
+ INIT_KFIFO(rpc->aer_fifo);
set_service_data(dev, rpc);
status = devm_request_threaded_irq(device, dev->irq, aer_irq, aer_isr,
--
1.9.1
