diff mbox series

[net-next,v4,1/3] net: phy: refactor and better document phy_speeds function

Message ID 20231216161206.1729-2-ansuelsmth@gmail.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series net: add define to describe link speed modes | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1115 this patch: 1115
netdev/cc_maintainers success CCed 7 of 7 maintainers
netdev/build_clang success Errors and warnings before: 1142 this patch: 1142
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1142 this patch: 1142
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 62 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Christian Marangi Dec. 16, 2023, 4:12 p.m. UTC
Refactor the phy_speeds function to be more readable and understandable
and add some documentation on it.

While on it extend it to take NULL speeds values to make it return only
the count of speed modes in the passed mask.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
 drivers/net/phy/phy-core.c | 50 ++++++++++++++++++++++++++++++++++----
 1 file changed, 45 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/phy/phy-core.c b/drivers/net/phy/phy-core.c
index 966c93cbe616..f3f5e4c41c97 100644
--- a/drivers/net/phy/phy-core.c
+++ b/drivers/net/phy/phy-core.c
@@ -317,17 +317,57 @@  phy_lookup_setting(int speed, int duplex, const unsigned long *mask, bool exact)
 }
 EXPORT_SYMBOL_GPL(phy_lookup_setting);
 
+/**
+ * phy_speeds - return all speeds in mask
+ * @speeds: pointer to array where to put the speed modes
+ * @size: size of array where to put the speed modes
+ * @mask: mask of speed modes to compare with
+ *
+ * Take mask, test bit in mask with the settings table and compose the
+ * speeds array based on that as many as size permits.
+ *
+ * With speeds NULL, only the number of detected modes is returned and
+ * no array is composed. (size value is ignored)
+ *
+ * Return: the number of detected modes in mask.
+ */
 size_t phy_speeds(unsigned int *speeds, size_t size,
 		  unsigned long *mask)
 {
+	unsigned int curr_speed;
 	size_t count;
 	int i;
 
-	for (i = 0, count = 0; i < ARRAY_SIZE(settings) && count < size; i++)
-		if (settings[i].bit < __ETHTOOL_LINK_MODE_MASK_NBITS &&
-		    test_bit(settings[i].bit, mask) &&
-		    (count == 0 || speeds[count - 1] != settings[i].speed))
-			speeds[count++] = settings[i].speed;
+	for (i = 0, count = 0; i < ARRAY_SIZE(settings); i++) {
+		/* Inconsistent mapping with ethtool modes? */
+		if (unlikely(settings[i].bit >= __ETHTOOL_LINK_MODE_MASK_NBITS))
+			return count;
+
+		/* Skip. Speed not in provided mask */
+		if (!test_bit(settings[i].bit, mask))
+			continue;
+
+		/* settings struct is set in descending order with
+		 * ordered speed modes. Detect a new speed mode by
+		 * checking if it's different than the current one.
+		 */
+		if (count == 0 || curr_speed != settings[i].speed) {
+			curr_speed = settings[i].speed;
+
+			/* With speeds not declared, we return only
+			 * the number of detected speed mode in the mask.
+			 */
+			if (speeds) {
+				/* No more space to put new modes */
+				if (count > size)
+					return count;
+
+				speeds[count] = curr_speed;
+			}
+
+			count++;
+		}
+	}
 
 	return count;
 }