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Diffstat (limited to 'sys-kernel/boest-v5.0.15/raspberrypi/0154-lan78xx-Debounce-link-events-to-minimize-poll-storm.patch')
-rw-r--r--sys-kernel/boest-v5.0.15/raspberrypi/0154-lan78xx-Debounce-link-events-to-minimize-poll-storm.patch46
1 files changed, 46 insertions, 0 deletions
diff --git a/sys-kernel/boest-v5.0.15/raspberrypi/0154-lan78xx-Debounce-link-events-to-minimize-poll-storm.patch b/sys-kernel/boest-v5.0.15/raspberrypi/0154-lan78xx-Debounce-link-events-to-minimize-poll-storm.patch
new file mode 100644
index 00000000..91877f6c
--- /dev/null
+++ b/sys-kernel/boest-v5.0.15/raspberrypi/0154-lan78xx-Debounce-link-events-to-minimize-poll-storm.patch
@@ -0,0 +1,46 @@
+From 1c0450b7886e2ddd33b696fa3513ebdd4270a18b Mon Sep 17 00:00:00 2001
+From: Joshua Emele <jemele@acm.org>
+Date: Wed, 7 Nov 2018 16:07:40 -0800
+Subject: [PATCH 154/194] lan78xx: Debounce link events to minimize poll storm
+
+The bInterval is set to 4 (i.e. 8 microframes => 1ms) and the only bit
+that the driver pays attention to is "link was reset". If there's a
+flapping status bit in that endpoint data, (such as if PHY negotiation
+needs a few tries to get a stable link) then polling at a slower rate
+would act as a de-bounce.
+
+See: https://github.com/raspberrypi/linux/issues/2447
+---
+ drivers/net/usb/lan78xx.c | 12 +++++++++++-
+ 1 file changed, 11 insertions(+), 1 deletion(-)
+
+diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
+index 3636e2b170a6..30629159a52e 100644
+--- a/drivers/net/usb/lan78xx.c
++++ b/drivers/net/usb/lan78xx.c
+@@ -437,6 +437,11 @@ static bool enable_tso;
+ module_param(enable_tso, bool, 0644);
+ MODULE_PARM_DESC(enable_tso, "Enables TCP segmentation offload");
+
++#define INT_URB_MICROFRAMES_PER_MS 8
++static int int_urb_interval_ms = 8;
++module_param(int_urb_interval_ms, int, 0);
++MODULE_PARM_DESC(int_urb_interval_ms, "Override usb interrupt urb interval");
++
+ static int lan78xx_read_reg(struct lan78xx_net *dev, u32 index, u32 *data)
+ {
+ u32 *buf = kmalloc(sizeof(u32), GFP_KERNEL);
+@@ -3814,7 +3819,12 @@ static int lan78xx_probe(struct usb_interface *intf,
+ dev->pipe_intr = usb_rcvintpipe(dev->udev,
+ dev->ep_intr->desc.bEndpointAddress &
+ USB_ENDPOINT_NUMBER_MASK);
+- period = dev->ep_intr->desc.bInterval;
++ if (int_urb_interval_ms <= 0)
++ period = dev->ep_intr->desc.bInterval;
++ else
++ period = int_urb_interval_ms * INT_URB_MICROFRAMES_PER_MS;
++
++ netif_notice(dev, probe, netdev, "int urb period %d\n", period);
+
+ maxp = usb_maxpacket(dev->udev, dev->pipe_intr, 0);
+ buf = kmalloc(maxp, GFP_KERNEL);