Re: [PATCHv3 3/3] CDC-NCM: record speed in status method

[Grant Grundler <grundler@chromium.org>]

[-- Attachment #1: Type: text/plain, Size: 2685 bytes --]

Oliver,
Can you include a 4th patch in the series to bring cdc_ether driver in
line with the cdc_ncm behavior?

I apologize for not including the patch inline - but it's late and I
don't want to fight with gmail at this point. Patch is attached. Not
tested.

cheers,
grant

On Thu, Feb 18, 2021 at 10:21 AM Oliver Neukum <oneukum@suse.com> wrote:
>
> The driver has a status method for receiving speed updates.
> The framework, however, had support functions only for devices
> that reported their speed upon an explicit query over a MDIO
> interface.
> CDC_NCM however gets direct notifications from the device.
> As new support functions have become available, we shall now
> record such notifications and tell the usbnet framework
> to make direct use of them without going through the PHY layer.
>
> v2: rebased on upstream
> v3: changed variable names
>
> Signed-off-by: Oliver Neukum <oneukum@suse.com>
> Tested-by: Roland Dreier <roland@kernel.org>
> ---
>  drivers/net/usb/cdc_ncm.c | 23 +----------------------
>  1 file changed, 1 insertion(+), 22 deletions(-)
>
> diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
> index 0d26cbeb6e04..74c1a86b1a71 100644
> --- a/drivers/net/usb/cdc_ncm.c
> +++ b/drivers/net/usb/cdc_ncm.c
> @@ -1829,30 +1829,9 @@ 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;
> -
> +        /* RTL8156 shipped before 2021 sends notification about every 32ms. */
>         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.
> -        */
> -       if ((tx_speed > 1000000) && (rx_speed > 1000000)) {
> -               netif_info(dev, link, dev->net,
> -                          "%u mbit/s downlink %u mbit/s uplink\n",
> -                          (unsigned int)(rx_speed / 1000000U),
> -                          (unsigned int)(tx_speed / 1000000U));
> -       } else {
> -               netif_info(dev, link, dev->net,
> -                          "%u kbit/s downlink %u kbit/s uplink\n",
> -                          (unsigned int)(rx_speed / 1000U),
> -                          (unsigned int)(tx_speed / 1000U));
> -       }
>  }
>
>  static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
> --
> 2.26.2
>

[-- Attachment #2: 0001-net-cdc_ether-record-speed-in-status-method.patch --]
[-- Type: text/x-patch, Size: 3555 bytes --]

From e5ac528c08bb35b25cbbf9a5e91d2491100e6763 Mon Sep 17 00:00:00 2001
From: Grant Grundler <Grant Grundler grundler@chromium.org>
Date: Wed, 17 Feb 2021 20:55:57 -0800
Subject: [PATCH] net: cdc_ether: record speed in status method

Until very recently, the usbnet framework only had support functions
for devices which reported the link speed by explicitly querying the
PHY over a MDIO interface. However, the cdc_ether devices send
notifications when the link state or link speeds change and do not
expose the PHY (or modem) directly.

Support funtions (e.g. usbnet_get_link_ksettings_internal()) to directly
query state recorded by the cdc_ether driver were added in a previous patch.

So instead of cdc_ether spewing the link speed into the dmesg buffer,
record the link speed encoded in these notifications and tell the
usbnet framework to use the new functions to get link speed/state.

Signed-off-by: Grant Grundler <grundler@chromium.org>
---
 drivers/net/usb/cdc_ether.c | 27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c
index a9b551028659..e13e9b799432 100644
--- a/drivers/net/usb/cdc_ether.c
+++ b/drivers/net/usb/cdc_ether.c
@@ -92,6 +92,18 @@ void usbnet_cdc_update_filter(struct usbnet *dev)
 }
 EXPORT_SYMBOL_GPL(usbnet_cdc_update_filter);
 
+/* We need to override usbnet_*_link_ksettings in bind() */
+static const struct ethtool_ops cdc_ether_ethtool_ops = {
+	.get_link		= usbnet_get_link,
+	.nway_reset		= usbnet_nway_reset,
+	.get_drvinfo		= usbnet_get_drvinfo,
+	.get_msglevel		= usbnet_get_msglevel,
+	.set_msglevel		= usbnet_set_msglevel,
+	.get_ts_info		= ethtool_op_get_ts_info,
+	.get_link_ksettings	= usbnet_get_link_ksettings_internal,
+	.set_link_ksettings	= NULL,
+};
+
 /* probes control interface, claims data interface, collects the bulk
  * endpoints, activates data interface (if needed), maybe sets MTU.
  * all pure cdc, except for certain firmware workarounds, and knowing
@@ -310,6 +322,9 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
 		return -ENODEV;
 	}
 
+	/* override ethtool_ops */
+	dev->net->ethtool_ops = &cdc_ether_ethtool_ops;
+
 	return 0;
 
 bad_desc:
@@ -379,12 +394,10 @@ EXPORT_SYMBOL_GPL(usbnet_cdc_unbind);
  * (by Brad Hards) talked with, with more functionality.
  */
 
-static void dumpspeed(struct usbnet *dev, __le32 *speeds)
+static void speed_change(struct usbnet *dev, __le32 *speeds)
 {
-	netif_info(dev, timer, dev->net,
-		   "link speeds: %u kbps up, %u kbps down\n",
-		   __le32_to_cpu(speeds[0]) / 1000,
-		   __le32_to_cpu(speeds[1]) / 1000);
+	dev->tx_speed = __le32_to_cpu(speeds[0]);
+	dev->rx_speed = __le32_to_cpu(speeds[1]);
 }
 
 void usbnet_cdc_status(struct usbnet *dev, struct urb *urb)
@@ -396,7 +409,7 @@ void usbnet_cdc_status(struct usbnet *dev, struct urb *urb)
 
 	/* SPEED_CHANGE can get split into two 8-byte packets */
 	if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
-		dumpspeed(dev, (__le32 *) urb->transfer_buffer);
+		speed_change(dev, (__le32 *) urb->transfer_buffer);
 		return;
 	}
 
@@ -413,7 +426,7 @@ void usbnet_cdc_status(struct usbnet *dev, struct urb *urb)
 		if (urb->actual_length != (sizeof(*event) + 8))
 			set_bit(EVENT_STS_SPLIT, &dev->flags);
 		else
-			dumpspeed(dev, (__le32 *) &event[1]);
+			speed_change(dev, (__le32 *) &event[1]);
 		break;
 	/* USB_CDC_NOTIFY_RESPONSE_AVAILABLE can happen too (e.g. RNDIS),
 	 * but there are no standard formats for the response data.
-- 
2.30.0