From: Grant Grundler <grundler@chromium.org>
To: Oliver Neukum <oliver@neukum.org>
Cc: "David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-usb@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org,
Grant Grundler <grundler@chromium.org>
Subject: [PATCH 3/3] net: usb: cdc_ncm: don't spew notifications
Date: Fri, 15 Jan 2021 21:26:23 -0800 [thread overview]
Message-ID: <20210116052623.3196274-3-grundler@chromium.org> (raw)
In-Reply-To: <20210116052623.3196274-1-grundler@chromium.org>
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>
---
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 25498c311551..5de096545b86 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 88a7673894d5..cfbfd6fe01df 100644
--- a/include/linux/usb/usbnet.h
+++ b/include/linux/usb/usbnet.h
@@ -81,6 +81,8 @@ 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)
--
2.29.2
next prev parent reply other threads:[~2021-01-16 5:28 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-16 5:26 [PATCH 1/3] net: usb: cdc_ncm: emit dev_err on error paths Grant Grundler
2021-01-16 5:26 ` [PATCH 2/3] net: usb: log errors to dmesg/syslog Grant Grundler
2021-01-18 22:02 ` Grant Grundler
2021-01-16 5:26 ` Grant Grundler [this message]
2021-01-18 22:02 ` [PATCH 3/3] net: usb: cdc_ncm: don't spew notifications Grant Grundler
2021-01-19 1:23 ` Hayes Wang
2021-01-19 21:45 ` Jakub Kicinski
2021-01-20 0:55 ` Grant Grundler
2021-01-20 0:59 ` Grant Grundler
2021-01-20 1:05 ` Jakub Kicinski
2021-01-20 1:14 ` Grant Grundler
2021-01-18 22:01 ` [PATCH 1/3] net: usb: cdc_ncm: emit dev_err on error paths Grant Grundler
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