| From 28dc578a8fd531f87525819325c99a8afbf6e778 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Tue, 19 Jan 2021 17:12:08 -0800 |
| Subject: net: usb: cdc_ncm: don't spew notifications |
| |
| From: Grant Grundler <grundler@chromium.org> |
| |
| [ Upstream commit de658a195ee23ca6aaffe197d1d2ea040beea0a2 ] |
| |
| RTL8156 sends notifications about every 32ms. |
| Only display/log notifications when something changes. |
| |
| This issue has been reported by others: |
| https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1832472 |
| https://lkml.org/lkml/2020/8/27/1083 |
| |
| ... |
| [785962.779840] usb 1-1: new high-speed USB device number 5 using xhci_hcd |
| [785962.929944] usb 1-1: New USB device found, idVendor=0bda, idProduct=8156, bcdDevice=30.00 |
| [785962.929949] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=6 |
| [785962.929952] usb 1-1: Product: USB 10/100/1G/2.5G LAN |
| [785962.929954] usb 1-1: Manufacturer: Realtek |
| [785962.929956] usb 1-1: SerialNumber: 000000001 |
| [785962.991755] usbcore: registered new interface driver cdc_ether |
| [785963.017068] cdc_ncm 1-1:2.0: MAC-Address: 00:24:27:88:08:15 |
| [785963.017072] cdc_ncm 1-1:2.0: setting rx_max = 16384 |
| [785963.017169] cdc_ncm 1-1:2.0: setting tx_max = 16384 |
| [785963.017682] cdc_ncm 1-1:2.0 usb0: register 'cdc_ncm' at usb-0000:00:14.0-1, CDC NCM, 00:24:27:88:08:15 |
| [785963.019211] usbcore: registered new interface driver cdc_ncm |
| [785963.023856] usbcore: registered new interface driver cdc_wdm |
| [785963.025461] usbcore: registered new interface driver cdc_mbim |
| [785963.038824] cdc_ncm 1-1:2.0 enx002427880815: renamed from usb0 |
| [785963.089586] cdc_ncm 1-1:2.0 enx002427880815: network connection: disconnected |
| [785963.121673] cdc_ncm 1-1:2.0 enx002427880815: network connection: disconnected |
| [785963.153682] cdc_ncm 1-1:2.0 enx002427880815: network connection: disconnected |
| ... |
| |
| This is about 2KB per second and will overwrite all contents of a 1MB |
| dmesg buffer in under 10 minutes rendering them useless for debugging |
| many kernel problems. |
| |
| This is also an extra 180 MB/day in /var/logs (or 1GB per week) rendering |
| the majority of those logs useless too. |
| |
| When the link is up (expected state), spew amount is >2x higher: |
| ... |
| [786139.600992] cdc_ncm 2-1:2.0 enx002427880815: network connection: connected |
| [786139.632997] cdc_ncm 2-1:2.0 enx002427880815: 2500 mbit/s downlink 2500 mbit/s uplink |
| [786139.665097] cdc_ncm 2-1:2.0 enx002427880815: network connection: connected |
| [786139.697100] cdc_ncm 2-1:2.0 enx002427880815: 2500 mbit/s downlink 2500 mbit/s uplink |
| [786139.729094] cdc_ncm 2-1:2.0 enx002427880815: network connection: connected |
| [786139.761108] cdc_ncm 2-1:2.0 enx002427880815: 2500 mbit/s downlink 2500 mbit/s uplink |
| ... |
| |
| Chrome OS cannot support RTL8156 until this is fixed. |
| |
| Signed-off-by: Grant Grundler <grundler@chromium.org> |
| Reviewed-by: Hayes Wang <hayeswang@realtek.com> |
| Link: https://lore.kernel.org/r/20210120011208.3768105-1-grundler@chromium.org |
| Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/net/usb/cdc_ncm.c | 12 +++++++++++- |
| include/linux/usb/usbnet.h | 2 ++ |
| 2 files changed, 13 insertions(+), 1 deletion(-) |
| |
| diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c |
| index 854c6624e685..1d3bf810f2ca 100644 |
| --- a/drivers/net/usb/cdc_ncm.c |
| +++ b/drivers/net/usb/cdc_ncm.c |
| @@ -1827,6 +1827,15 @@ cdc_ncm_speed_change(struct usbnet *dev, |
| uint32_t rx_speed = le32_to_cpu(data->DLBitRRate); |
| uint32_t tx_speed = le32_to_cpu(data->ULBitRate); |
| |
| + /* if the speed hasn't changed, don't report it. |
| + * RTL8156 shipped before 2021 sends notification about every 32ms. |
| + */ |
| + if (dev->rx_speed == rx_speed && dev->tx_speed == tx_speed) |
| + return; |
| + |
| + dev->rx_speed = rx_speed; |
| + dev->tx_speed = tx_speed; |
| + |
| /* |
| * Currently the USB-NET API does not support reporting the actual |
| * device speed. Do print it instead. |
| @@ -1867,7 +1876,8 @@ static void cdc_ncm_status(struct usbnet *dev, struct urb *urb) |
| * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be |
| * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE. |
| */ |
| - usbnet_link_change(dev, !!event->wValue, 0); |
| + if (netif_carrier_ok(dev->net) != !!event->wValue) |
| + usbnet_link_change(dev, !!event->wValue, 0); |
| break; |
| |
| case USB_CDC_NOTIFY_SPEED_CHANGE: |
| diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h |
| index 2e4f7721fc4e..8110c29fab42 100644 |
| --- a/include/linux/usb/usbnet.h |
| +++ b/include/linux/usb/usbnet.h |
| @@ -83,6 +83,8 @@ struct usbnet { |
| # define EVENT_LINK_CHANGE 11 |
| # define EVENT_SET_RX_MODE 12 |
| # define EVENT_NO_IP_ALIGN 13 |
| + u32 rx_speed; /* in bps - NOT Mbps */ |
| + u32 tx_speed; /* in bps - NOT Mbps */ |
| }; |
| |
| static inline struct usb_driver *driver_of(struct usb_interface *intf) |
| -- |
| 2.30.2 |
| |