lkml.org 
[lkml]   [2017]   [Sep]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v3] PCIe AER: report uncorrectable errors only to the functions that logged the errors
On Thu, Sep 28, 2017 at 03:33:05PM +0100, Gabriele Paoloni wrote:
> Currently if an uncorrectable error is reported by an EP the AER
> driver walks over all the devices connected to the upstream port
> bus and in turns call the report_error_detected() callback.
> If any of the devices connected to the bus does not implement
> dev->driver->err_handler->error_detected() do_recovery() will fail
> leaving all the bus hierarchy devices unrecovered.
>
> According to section "6.2.2.2.2. Non-Fatal Errors" of the PCIe specs
> << Non-fatal errors are uncorrectable errors which cause a particular
> transaction to be unreliable but the Link is otherwise fully functional.
> Isolating Non-fatal from Fatal errors provides Requester/Receiver logic
> in a device or system management software the opportunity to recover
> from the error without resetting the components on the Link and
> disturbing other transactions in progress. Devices not associated with
> the transaction in error are not impacted by the error.>>
> therefore for non fatal errors the PCIe link should not be considered
> compromised and it makes sense to report the error only to all the
> functions that logged an error.
>
> This patch implements this new behaviour for non fatal errors.
> Also this patch fixes a bug (filed as in the link below)
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=197055
> Fixes: 6c2b374d7485 ("PCI-Express AER implemetation: AER core and aerdriver")
> Signed-off-by: Gabriele Paoloni <gabriele.paoloni@huawei.com>
> Signed-off-by: Dongdong Liu <liudongdong3@huawei.com>

Applied to pci/aer for v4.15, thanks!

I rewrote some of the changelog to say "non-fatal" instead of
"uncorrectable", since "uncorrectable" also includes fatal errors,
and you're not changing those. Take a look and let me know if
I broke anything.

> ---
> Changes from v2:
> - no functional changes
> - Added reference in the commit log to the bugzilla ticket
> - Added reference in the commit log the commit that this patch fixes
> - Added reference in the commit log to the PCIe specs for Non-fatal
> error handling rules
>
> Changes from v1:
> - now errors are reported only to the fucntions that logged the error
> instead of all the functions in the same device.
> - the patch subject has changed to match the new implementation
> ---
> drivers/pci/pcie/aer/aerdrv_core.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/pcie/aer/aerdrv_core.c b/drivers/pci/pcie/aer/aerdrv_core.c
> index 890efcc..7448052 100644
> --- a/drivers/pci/pcie/aer/aerdrv_core.c
> +++ b/drivers/pci/pcie/aer/aerdrv_core.c
> @@ -390,7 +390,14 @@ static pci_ers_result_t broadcast_error_message(struct pci_dev *dev,
> * If the error is reported by an end point, we think this
> * error is related to the upstream link of the end point.
> */
> - pci_walk_bus(dev->bus, cb, &result_data);
> + if (state == pci_channel_io_normal)
> + /*
> + * the error is non fatal so the bus is ok, just invoke
> + * the callback for the function that logged the error.
> + */
> + cb(dev, &result_data);
> + else
> + pci_walk_bus(dev->bus, cb, &result_data);
> }
>
> return result_data.result;
> --
> 2.7.4
>
>

\
 
 \ /
  Last update: 2017-09-29 23:16    [W:0.067 / U:32.056 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site