Revision 2 of the Device Feature List (DFL) Port feature has
slightly different requirements than revision 1. Revision 2
does not need the port to reset at driver startup. In fact,
performing a port reset during driver initialization can cause
driver race conditions when the port is connected to a different
PCIe Physical Function (PF) than the management PF performing
the actual port reset.
Signed-off-by: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
---
drivers/fpga/dfl-afu-main.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c
index c0a75ca360d6..7d7f80cd264f 100644
--- a/drivers/fpga/dfl-afu-main.c
+++ b/drivers/fpga/dfl-afu-main.c
@@ -417,7 +417,18 @@ static const struct attribute_group port_hdr_group = {
static int port_hdr_init(struct platform_device *pdev,
struct dfl_feature *feature)
{
- port_reset(pdev);
+ void __iomem *base;
+ u8 rev;
+
+ base = dfl_get_feature_ioaddr_by_id(&pdev->dev, PORT_FEATURE_ID_HEADER);
+
+ rev = dfl_feature_revision(base);
+
+ if (rev < 2)
+ port_reset(pdev);
+
+ if (rev > 2)
+ dev_info(&pdev->dev, "unexpected port feature revision, %u\n", rev);
return 0;
}
--
2.34.1
