From: Matthew Gerlach <matthew.gerlach@linux.intel.com>
To: hao.wu@intel.com, trix@redhat.com, mdf@kernel.org,
yilun.xu@intel.com, linux-fpga@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Subject: [PATCH] fpga: dfl: afu: update initialization of port_hdr driver
Date: Mon, 22 Jan 2024 09:24:33 -0800 [thread overview]
Message-ID: <20240122172433.537525-1-matthew.gerlach@linux.intel.com> (raw)
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@linux.intel.com>
---
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
next reply other threads:[~2024-01-22 17:24 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-22 17:24 Matthew Gerlach [this message]
2024-01-23 2:20 ` [PATCH] fpga: dfl: afu: update initialization of port_hdr driver Xu Yilun
2024-01-24 19:40 ` matthew.gerlach
2024-01-30 9:35 ` Xu Yilun
2024-01-30 17:13 ` matthew.gerlach
2024-01-31 4:59 ` Xu Yilun
2024-01-31 23:53 ` matthew.gerlach
2024-02-05 2:51 ` Xu Yilun
2024-02-05 23:30 ` matthew.gerlach
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