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From:   Rajneesh Bhardwaj <rajneesh.bhardwaj@linux.intel.com>
To:     platform-driver-x86@vger.kernel.org
Cc:     dvhart@infradead.org, andy@infradead.org,
        linux-kernel@vger.kernel.org, rajneesh.bhardwaj@intel.com,
        Rajneesh Bhardwaj <rajneesh.bhardwaj@linux.intel.com>,
        Matt Turner <matt.turner@intel.com>,
        Len Brown <len.brown@intel.com>,
        Souvik Kumar Chakravarty <souvik.k.chakravarty@intel.com>,
        Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@intel.com>
Subject: [PATCH v2 4/4] platform/x86: intel_telemetry: report debugfs failure
Date:   Sat,  6 Oct 2018 12:21:13 +0530
Message-Id: <20181006065113.669-4-rajneesh.bhardwaj@linux.intel.com>
In-Reply-To: <20181006065113.669-1-rajneesh.bhardwaj@linux.intel.com>
References: <20181006065113.669-1-rajneesh.bhardwaj@linux.intel.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On some Goldmont based systems such as ASRock J3455M the BIOS may not
enable the IPC1 device that provides access to the PMC and PUNIT. In
such scenarios, the IOSS and PSS resources from the platform device can
not be obtained and result in a invalid telemetry_plt_config which is an
internal data structure that holds platform config and is maintained by
the telemetry platform driver.

This is also applicable to the platforms where the BIOS supports IPC1
device under debug configurations but IPC1 is disabled by user or the
policy.

This change allows user to know the reason for not seeing entries under
/sys/kernel/debug/telemetry/* when there is no apparent failure at boot.

Cc: Matt Turner <matt.turner@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Souvik Kumar Chakravarty <souvik.k.chakravarty@intel.com>
Cc: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@intel.com>

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=198779
Acked-by: Matt Turner <matt.turner@intel.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@linux.intel.com>
---
Changes in v2:
 * Removed print and out label both as suggested by Andy.
 * changed to pr_info.
 * Other minor style fixes.


 drivers/platform/x86/intel_telemetry_debugfs.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/intel_telemetry_debugfs.c b/drivers/platform/x86/intel_telemetry_debugfs.c
index ffd0474b0531..1423fa8710fd 100644
--- a/drivers/platform/x86/intel_telemetry_debugfs.c
+++ b/drivers/platform/x86/intel_telemetry_debugfs.c
@@ -951,12 +951,16 @@ static int __init telemetry_debugfs_init(void)
 	debugfs_conf = (struct telemetry_debugfs_conf *)id->driver_data;
 
 	err = telemetry_pltconfig_valid();
-	if (err < 0)
+	if (err < 0) {
+		pr_info("Invalid pltconfig, ensure IPC1 device is enabled in BIOS\n");
 		return -ENODEV;
+	}
 
 	err = telemetry_debugfs_check_evts();
-	if (err < 0)
+	if (err < 0) {
+		pr_info("telemetry_debugfs_check_evts failed\n");
 		return -EINVAL;
+	}
 
 	register_pm_notifier(&pm_notifier);
 
-- 
2.17.1