diff mbox series

[net-next,5/7] r8169: improve interrupt coalescing parameter handling

Message ID b929adc1-75e1-ba74-64e6-1db1f7b0e485@gmail.com
State Accepted
Delegated to: David Miller
Headers show
Series r8169: refactor and improve interrupt coalescing | expand

Commit Message

Heiner Kallweit April 30, 2020, 7:58 p.m. UTC
The chip supports only frame limits 0, 4, 8, .. 60 internally.
Returning EINVAL for all val % 4 != 0 seems to be a little bit too
unfriendly to the user. Therefore round up the frame limit to the next
supported value. In addition round up the time limit, else a very low
limit could be rounded down to 0, and interpreted as "ignore value"
by the chip.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/net/ethernet/realtek/r8169_main.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index a95615684..fe95c47e7 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -1909,21 +1909,21 @@  static int rtl_set_coalesce(struct net_device *dev, struct ethtool_coalesce *ec)
 		 * - then user does `ethtool -C eth0 rx-usecs 100`
 		 *
 		 * since ethtool sends to kernel whole ethtool_coalesce
-		 * settings, if we do not handle rx_usecs=!0, rx_frames=1
-		 * we'll reject it below in `frames % 4 != 0`.
+		 * settings, if we want to ignore rx_frames then it has
+		 * to be set to 0.
 		 */
 		if (p->frames == 1) {
 			p->frames = 0;
 		}
 
-		units = p->usecs * 1000 / scale;
-		if (p->frames > RTL_COALESCE_FRAME_MAX || p->frames % 4)
-			return -EINVAL;
+		units = DIV_ROUND_UP(p->usecs * 1000, scale);
+		if (p->frames > RTL_COALESCE_FRAME_MAX)
+			return -ERANGE;
 
 		w <<= RTL_COALESCE_SHIFT;
 		w |= units;
 		w <<= RTL_COALESCE_SHIFT;
-		w |= p->frames >> 2;
+		w |= DIV_ROUND_UP(p->frames, 4);
 	}
 
 	rtl_lock_work(tp);