linux-kernel - [PATCH 2/2] platform/mellanox: mlxbf-pmc: Ignore unsupported performance blocks

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Date: Thu, 22 Feb 2024 15:57:30 -0500
From: Luiz Capitulino <luizcap@...hat.com>
To: ilpo.jarvinen@...ux.intel.com,
	shravankr@...dia.com
Cc: davthompson@...dia.com,
	ndalvi@...hat.com,
	linux-kernel@...r.kernel.org,
	platform-driver-x86@...r.kernel.org,
	Luiz Capitulino <luizcap@...hat.com>
Subject: [PATCH 2/2] platform/mellanox: mlxbf-pmc: Ignore unsupported performance blocks

Currently, the driver has two behaviors to deal with new & unsupported
performance blocks reported by the firmware:

 1. For register and unknown block types, the driver will fail to load
    with the following error message:

    [ 4510.956369] mlxbf-pmc: probe of MLNXBFD2:00 failed with error -22

 2. For counter and crspace blocks, the driver will load and sysfs files
    will be created but getting the contents of event_list or trying to
    setup the counter will fail

Instead, let's ignore and log unsupported blocks. This means the driver
will always load and unsupported blocks will never show up in sysfs.

Signed-off-by: Luiz Capitulino <luizcap@...hat.com>
---
 drivers/platform/mellanox/mlxbf-pmc.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/mellanox/mlxbf-pmc.c b/drivers/platform/mellanox/mlxbf-pmc.c
index b71636eb3db1..746567767e5b 100644
--- a/drivers/platform/mellanox/mlxbf-pmc.c
+++ b/drivers/platform/mellanox/mlxbf-pmc.c
@@ -1043,6 +1043,11 @@ static const struct mlxbf_pmc_events *mlxbf_pmc_event_list(const char *blk, size
 	return events;
 }
 
+static bool mlxbf_pmc_event_supported(const char *blk)
+{
+	return !!mlxbf_pmc_event_list(blk, NULL);
+}
+
 /* Get the event number given the name */
 static int mlxbf_pmc_get_event_num(const char *blk, const char *evt)
 {
@@ -1761,6 +1766,9 @@ static int mlxbf_pmc_init_perftype_counter(struct device *dev, unsigned int blk_
 	struct mlxbf_pmc_attribute *attr;
 	unsigned int i = 0, j = 0;
 
+	if (!mlxbf_pmc_event_supported(pmc->block_name[blk_num]))
+		return -ENOENT;
+
 	/* "event_list" sysfs to list events supported by the block */
 	attr = &pmc->block[blk_num].attr_event_list;
 	attr->dev_attr.attr.mode = 0444;
@@ -1840,7 +1848,7 @@ static int mlxbf_pmc_init_perftype_reg(struct device *dev, unsigned int blk_num)
 
 	events = mlxbf_pmc_event_list(pmc->block_name[blk_num], &count);
 	if (!events)
-		return -EINVAL;
+		return -ENOENT;
 
 	pmc->block[blk_num].attr_event = devm_kcalloc(
 		dev, count, sizeof(struct mlxbf_pmc_attribute), GFP_KERNEL);
@@ -1878,7 +1886,7 @@ static int mlxbf_pmc_create_groups(struct device *dev, unsigned int blk_num)
 	else if (pmc->block[blk_num].type == MLXBF_PMC_TYPE_REGISTER)
 		err = mlxbf_pmc_init_perftype_reg(dev, blk_num);
 	else
-		err = -EINVAL;
+		err = -ENOENT;
 
 	if (err)
 		return err;
@@ -1983,6 +1991,10 @@ static int mlxbf_pmc_map_counters(struct device *dev)
 			return -ENOMEM;
 
 		ret = mlxbf_pmc_create_groups(dev, i);
+		if (ret == -ENOENT) {
+			dev_warn(dev, "ignoring unsupported block: '%s'\n", pmc->block_name[i]);
+			continue;
+		}
 		if (ret)
 			return ret;
 	}
-- 
2.43.1