diff options
| author | Hardik Gajjar <hgajjar@de.adit-jv.com> | 2023-10-27 17:20:29 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-11-23 12:32:44 +0000 |
| commit | 5a1ccf0c72cf917ff3ccc131d1bb8d19338ffe52 (patch) | |
| tree | 75881d4873f75c6540d93faf40fad08fb81a399c /Documentation/admin-guide/kernel-parameters.txt | |
| parent | a769154c7cac037914ba375ae88aae55b2c853e0 (diff) | |
usb: new quirk to reduce the SET_ADDRESS request timeout
This patch introduces a new USB quirk,
USB_QUIRK_SHORT_SET_ADDRESS_REQ_TIMEOUT, which modifies the timeout value
for the SET_ADDRESS request. The standard timeout for USB request/command
is 5000 ms, as recommended in the USB 3.2 specification (section 9.2.6.1).
However, certain scenarios, such as connecting devices through an APTIV
hub, can lead to timeout errors when the device enumerates as full speed
initially and later switches to high speed during chirp negotiation.
In such cases, USB analyzer logs reveal that the bus suspends for
5 seconds due to incorrect chirp parsing and resumes only after two
consecutive timeout errors trigger a hub driver reset.
Packet(54) Dir(?) Full Speed J(997.100 us) Idle( 2.850 us)
_______| Time Stamp(28 . 105 910 682)
_______|_____________________________________________________________Ch0
Packet(55) Dir(?) Full Speed J(997.118 us) Idle( 2.850 us)
_______| Time Stamp(28 . 106 910 632)
_______|_____________________________________________________________Ch0
Packet(56) Dir(?) Full Speed J(399.650 us) Idle(222.582 us)
_______| Time Stamp(28 . 107 910 600)
_______|_____________________________________________________________Ch0
Packet(57) Dir Chirp J( 23.955 ms) Idle(115.169 ms)
_______| Time Stamp(28 . 108 532 832)
_______|_____________________________________________________________Ch0
Packet(58) Dir(?) Full Speed J (Suspend)( 5.347 sec) Idle( 5.366 us)
_______| Time Stamp(28 . 247 657 600)
_______|_____________________________________________________________Ch0
This 5-second delay in device enumeration is undesirable, particularly
in automotive applications where quick enumeration is crucial
(ideally within 3 seconds).
The newly introduced quirks provide the flexibility to align with a
3-second time limit, as required in specific contexts like automotive
applications.
By reducing the SET_ADDRESS request timeout to 500 ms, the
system can respond more swiftly to errors, initiate rapid recovery, and
ensure efficient device enumeration. This change is vital for scenarios
where rapid smartphone enumeration and screen projection are essential.
To use the quirk, please write "vendor_id:product_id:p" to
/sys/bus/usb/drivers/hub/module/parameter/quirks
For example,
echo "0x2c48:0x0132:p" > /sys/bus/usb/drivers/hub/module/parameters/quirks"
Signed-off-by: Hardik Gajjar <hgajjar@de.adit-jv.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20231027152029.104363-2-hgajjar@de.adit-jv.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 65731b060e3f..0a6a4b7f7a3b 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6908,6 +6908,9 @@ pause after every control message); o = USB_QUIRK_HUB_SLOW_RESET (Hub needs extra delay after resetting its port); + p = USB_QUIRK_SHORT_SET_ADDRESS_REQ_TIMEOUT + (Reduce timeout of the SET_ADDRESS + request from 5000 ms to 500 ms); Example: quirks=0781:5580:bk,0a5c:5834:gij usbhid.mousepoll= |