diff options
| author | Lorenzo Colitti <lorenzo@google.com> | 2020-08-19 01:19:49 +0900 |
|---|---|---|
| committer | Felipe Balbi <balbi@kernel.org> | 2020-10-02 09:57:41 +0300 |
| commit | 4eea21dc67b0c6ba15ae41b1defa113a680a858e (patch) | |
| tree | 4442b543ae27fe063ac3cb12fd559bdf6a69eab5 | |
| parent | d98ef43bfb65b5201e1afe36aaf8c4f9d71b4307 (diff) | |
| download | linux-4eea21dc67b0c6ba15ae41b1defa113a680a858e.tar.bz2 | |
usb: gadget: u_ether: enable qmult on SuperSpeed Plus as well
The u_ether driver has a qmult setting that multiplies the
transmit queue length (which by default is 2).
The intent is that it should be enabled at high/super speed, but
because the code does not explicitly check for USB_SUPER_PLUS,
it is disabled at that speed.
Fix this by ensuring that the queue multiplier is enabled for any
wired link at high speed or above. Using >= for USB_SPEED_*
constants seems correct because it is what the gadget_is_xxxspeed
functions do.
The queue multiplier substantially helps performance at higher
speeds. On a direct SuperSpeed Plus link to a Linux laptop,
iperf3 single TCP stream:
Before (qmult=1): 1.3 Gbps
After (qmult=5): 3.2 Gbps
Fixes: 04617db7aa68 ("usb: gadget: add SS descriptors to Ethernet gadget")
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
| -rw-r--r-- | drivers/usb/gadget/function/u_ether.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c index c3cc6bd14e61..31ea76adcc0d 100644 --- a/drivers/usb/gadget/function/u_ether.c +++ b/drivers/usb/gadget/function/u_ether.c @@ -93,7 +93,7 @@ struct eth_dev { static inline int qlen(struct usb_gadget *gadget, unsigned qmult) { if (gadget_is_dualspeed(gadget) && (gadget->speed == USB_SPEED_HIGH || - gadget->speed == USB_SPEED_SUPER)) + gadget->speed >= USB_SPEED_SUPER)) return qmult * DEFAULT_QLEN; else return DEFAULT_QLEN; |