Re: [PATCH RESEND] PCI/AER: Use a common function to print AER error bits

From: Alex G.
Date: Sat Apr 28 2018 - 12:46:50 EST

On 04/27/2018 05:43 PM, Bjorn Helgaas wrote:
On Tue, Apr 17, 2018 at 12:09:43PM -0500, Alexandru Gagniuc wrote:
On errors reported from CPER, cper_print_bits() was used to log the
AER bits. This resulted in hard-to-understand messages, without a
prefix. Instead use __aer_print_error() for both native AER and CPER
to provide a more consistent log format.

Signed-off-by: Alexandru Gagniuc <>
drivers/pci/pcie/aer/aerdrv_errprint.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/pcie/aer/aerdrv_errprint.c b/drivers/pci/pcie/aer/aerdrv_errprint.c
index cfc89dd57831..cfae4d52f848 100644
--- a/drivers/pci/pcie/aer/aerdrv_errprint.c
+++ b/drivers/pci/pcie/aer/aerdrv_errprint.c
@@ -216,28 +216,30 @@ EXPORT_SYMBOL_GPL(cper_severity_to_aer);
void cper_print_aer(struct pci_dev *dev, int aer_severity,
struct aer_capability_regs *aer)
- int layer, agent, status_strs_size, tlp_header_valid = 0;
+ int layer, agent, tlp_header_valid = 0;
u32 status, mask;
- const char **status_strs;
+ struct aer_err_info info;
if (aer_severity == AER_CORRECTABLE) {
status = aer->cor_status;
mask = aer->cor_mask;
- status_strs = aer_correctable_error_string;
- status_strs_size = ARRAY_SIZE(aer_correctable_error_string);
} else {
status = aer->uncor_status;
mask = aer->uncor_mask;
- status_strs = aer_uncorrectable_error_string;
- status_strs_size = ARRAY_SIZE(aer_uncorrectable_error_string);
tlp_header_valid = status & AER_LOG_TLP_MASKS;
layer = AER_GET_LAYER_ERROR(aer_severity, status);
agent = AER_GET_AGENT(aer_severity, status);
+ memset(&info, 0, sizeof(info));
+ info.severity = aer_severity;
+ info.status = status;
+ info.mask = mask;
+ info.first_error = 0x1f;

I like this patch a lot, but where does this "first_error = 0x1f" come

aer_(un)correctable_error_string don't go to [0x1f], so this guarantees us we don't print "(First)".

I assume this is supposed to be the "First Error Pointer" in the
Advanced Error Capabilities and Control register (PCIe r4.0, sec There is a "cap_control" field in struct
aer_capability_regs; should we be using that here?

There is a way to extract it from the PCI regs, and it's quite simple. IIRC, it should be all f's when the capability is not implemented. I wanted to avoid any further parsing of PCI regs in this patch.

I can see a way to use even more common printk code, but that requires validating the PCI regs we get from firmware. That means we need to make a guarantee about CPER that is beyond the scope of this patch.


pci_err(dev, "aer_status: 0x%08x, aer_mask: 0x%08x\n", status, mask);
- cper_print_bits("", status, status_strs, status_strs_size);
+ __aer_print_error(dev, &info);
pci_err(dev, "aer_layer=%s, aer_agent=%s\n",
aer_error_layer[layer], aer_agent_string[agent]);