On Tue, 31 May 2022, [email protected] wrote:
>From: Ira Weiny <[email protected]>
>
>The CDAT read may fail for a number of reasons but mainly it is possible
>to get different parts of a valid state. The checksum in the CDAT table
>protects against this.
>
>Now that the cdat data is validated issue a retries if the CDAT read
>fails. For now 5 retries are implemented.
>
>Signed-off-by: Ira Weiny <[email protected]>
>---
>Changes from V8
> Move code to cxl/core/pci.c
>
>Changes from V6
> Move to pci.c
> Fix retries count
> Change to 5 retries
>
>Changes from V5:
> New patch -- easy to push off or drop.
>---
> drivers/cxl/core/pci.c | 32 +++++++++++++++++++++-----------
> 1 file changed, 21 insertions(+), 11 deletions(-)
>
>diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
>index bb370df1cb6c..7f7dac9030a6 100644
>--- a/drivers/cxl/core/pci.c
>+++ b/drivers/cxl/core/pci.c
>@@ -620,20 +620,18 @@ static int cxl_cdat_read_table(struct cxl_port *port,
> return rc;
> }
>
>-void read_cdat_data(struct cxl_port *port)
>+static int __read_cdat_data(struct cxl_port *port)
> {
> struct device *dev = &port->dev;
> size_t cdat_length;
> int ret;
>
> if (cxl_cdat_get_length(port, &cdat_length))
>- return;
>+ return 0;
>
> port->cdat.table = devm_kzalloc(dev, cdat_length, GFP_KERNEL);
>- if (!port->cdat.table) {
>- ret = -ENOMEM;
>- goto error;
>- }
>+ if (!port->cdat.table)
>+ return -ENOMEM;
>
> port->cdat.length = cdat_length;
> ret = cxl_cdat_read_table(port, &port->cdat);
>@@ -641,12 +639,24 @@ void read_cdat_data(struct cxl_port *port)
> devm_kfree(dev, port->cdat.table);
> port->cdat.table = NULL;
> port->cdat.length = 0;
>- ret = -EIO;
>- goto error;
>+ return -EIO;
> }
>
>- return;
>-error:
>- dev_err(dev, "CDAT data read error (%d)\n", ret);
>+ return 0;
>+}
>+
>+void read_cdat_data(struct cxl_port *port)
>+{
>+ int retries = 5;
>+ int rc;
>+
>+ while (retries--) {
>+ rc = __read_cdat_data(port);
>+ if (!rc)
>+ break;
>+ dev_err(&port->dev,
>+ "CDAT data read error rc=%d (retries %d)\n",
>+ rc, retries);
>+ }
> }
> EXPORT_SYMBOL_NS_GPL(read_cdat_data, CXL);
Better a single final error message after exhausting all retries
instead of each time.
Thanks,
Davidlohr