Hi Greg,

-----Original Message-----
From: Greg KH <gregkh@linuxfoundation.org>
Sent: Wednesday, October 4, 2023 5:45 PM
To: Buddhabhatti, Jay <redacted>
Cc: Simek, Michal <michal.simek@amd.com>; Shah, Tanmay
[off-list ref]; Manne, Nava kishore
[off-list ref]; Levinsky, Ben [off-list ref];
robh@kernel.org; dhaval.r.shah@amd.com; marex@denx.de; Shaikh, Izhar
Ameer [off-list ref]; arnd@arndb.de;
ruanjinjie@huawei.com; mathieu.poirier@linaro.org; linux-
kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 4/6] drivers: soc: xilinx: Fix error message on SGI
registration failure

On Wed, Oct 04, 2023 at 02:41:14AM -0700, Jay Buddhabhatti wrote:

quoted

Failure to register SGI for firmware event notification is non-fatal
error when feature is not supported by other modules such as Xen and
TF-A. Add _info level log message for such special case.

Also add XST_PM_INVALID_VERSION error code and map it to -EOPNOSUPP
Linux kernel error code. If feature is not supported or EEMI API
version is mismatch, firmware can return XST_PM_INVALID_VERSION = 4 or
XST_PM_NO_FEATURE = 19 error code.

Co-developed-by: Tanmay Shah <redacted>
Signed-off-by: Tanmay Shah <redacted>
Signed-off-by: Jay Buddhabhatti <redacted>
---
 drivers/firmware/xilinx/zynqmp.c        | 4 +++-
 drivers/soc/xilinx/xlnx_event_manager.c | 7 ++++++-
 include/linux/firmware/xlnx-zynqmp.h    | 1 +
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/xilinx/zynqmp.c

b/drivers/firmware/xilinx/zynqmp.c
index 00ea2508f692..de09d77cf1e4 100644

--- a/drivers/firmware/xilinx/zynqmp.c
+++ b/drivers/firmware/xilinx/zynqmp.c

@@ -92,6 +92,8 @@ static int zynqmp_pm_ret_code(u32 ret_status)
 		return 0;
 	case XST_PM_NO_FEATURE:
 		return -ENOTSUPP;
+	case XST_PM_INVALID_VERSION:
+		return -EOPNOTSUPP;
 	case XST_PM_NO_ACCESS:
 		return -EACCES;
 	case XST_PM_ABORT_SUSPEND:

@@ -379,7 +381,7 @@ int zynqmp_pm_register_sgi(u32 sgi_num, u32 reset)

 	ret = zynqmp_pm_invoke_fn(TF_A_PM_REGISTER_SGI, sgi_num, reset,

0, 0,

quoted

 				  0, NULL);
-	if (!ret)
+	if (ret != -EOPNOTSUPP && !ret)
 		return ret;

 	/* try old implementation as fallback strategy if above fails */

diff --git a/drivers/soc/xilinx/xlnx_event_manager.c

b/drivers/soc/xilinx/xlnx_event_manager.c
index 38cfc161a713..bfa5cf4a0cab 100644

--- a/drivers/soc/xilinx/xlnx_event_manager.c
+++ b/drivers/soc/xilinx/xlnx_event_manager.c

@@ -653,7 +653,12 @@ static int xlnx_event_manager_probe(struct

platform_device *pdev)

 	ret = zynqmp_pm_register_sgi(sgi_num, 0);
 	if (ret) {
-		dev_err(&pdev->dev, "SGI %d Registration over TF-A failed with

%d\n", sgi_num, ret);

quoted

+		if (ret == -EOPNOTSUPP)
+			dev_info(&pdev->dev, "PM firmware event notification

not

quoted

+supported\n");

Why is this "info"?  Why not error?

[Jay] Because it is non-fatal error which will not cause kernel crash.

And what is userspace supposed to do with this information if it sees it?

[Jay] This message indicates that SGI registration is not supported by other modules like TF-A or Xen. So user need to use TF-A with this support if they want to use event management driver.

Thanks,
Jay

thanks,

greg k-h

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