On 2/8/24 12:30, Shantur Rathore wrote:
Hi Marek,
On Wed, Feb 7, 2024 at 1:07 PM Marek Vasut <ma...@denx.de> wrote:
On 2/7/24 11:23, Shantur Rathore wrote:
USB 3.0 spec requires hub to reset device while
enumeration. Some USB 2.0 hubs / devices don't
handle this well and after implementation of
reset some USB 2.0 disks weren't detected on
Allwinner based boards.
Resetting only when hub is USB 3.0 fixes it.
It would be good to include as many details about the faulty hardware in
the commit message as possible, so that when someone else runs into
this, they would have all that information available.
Tested-by: Andre Przywara <andre.przyw...@arm.com>
Signed-off-by: Shantur Rathore <i...@shantur.com>
---
common/usb_hub.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/common/usb_hub.c b/common/usb_hub.c
index 3fb7e14d10..2e054eb935 100644
--- a/common/usb_hub.c
+++ b/common/usb_hub.c
@@ -174,8 +174,10 @@ static void usb_hub_power_on(struct usb_hub_device *hub)
debug("enabling power on all ports\n");
for (i = 0; i < dev->maxchild; i++) {
- usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_RESET);
- debug("Reset : port %d returns %lX\n", i + 1, dev->status);
+ if (usb_hub_is_superspeed(dev)) {
Should this condition be "all which are lower than superspeed" instead ,
so when the next generation of USB comes, this problem won't trigger ?
What does Linux do btw ?
As of now Linux checks if the hub is superspeed
https://github.com/torvalds/linux/blob/master/drivers/usb/core/hub.c#L2859
which is
return hdev->descriptor.bDeviceProtocol == USB_HUB_PR_SS; // USB_HUB_PR_SS = 3
This holds true for newer SuperSpeedPlus hubs as well.
https://github.com/torvalds/linux/blob/master/drivers/usb/core/hub.h#L155
We can change the check to be bDeviceProtocol > 2 but who knows if
things change in the newer version of spec.
I am open to suggestions.
Please just include the ^ in the commit description. Use link to
git.kernel.org , not some mirror . This is extremely useful information
and, well, you already wrote the V2 commit message addition in this answer.
Thanks
