This is a note to let you know that I've just added the patch titled usb: musb: fix MUSB_QUIRK_B_DISCONNECT_99 handling to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: usb-musb-fix-musb_quirk_b_disconnect_99-handling.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From b65ba0c362be665192381cc59e3ac3ef6f0dd1e1 Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxx> Date: Fri, 28 May 2021 16:04:46 +0200 Subject: usb: musb: fix MUSB_QUIRK_B_DISCONNECT_99 handling From: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxx> commit b65ba0c362be665192381cc59e3ac3ef6f0dd1e1 upstream. In commit 92af4fc6ec33 ("usb: musb: Fix suspend with devices connected for a64"), the logic to support the MUSB_QUIRK_B_DISCONNECT_99 quirk was modified to only conditionally schedule the musb->irq_work delayed work. This commit badly breaks ECM Gadget on AM335X. Indeed, with this commit, one can observe massive packet loss: $ ping 192.168.0.100 ... 15 packets transmitted, 3 received, 80% packet loss, time 14316ms Reverting this commit brings back a properly functioning ECM Gadget. An analysis of the commit seems to indicate that a mistake was made: the previous code was not falling through into the MUSB_QUIRK_B_INVALID_VBUS_91, but now it is, unless the condition is taken. Changing the logic to be as it was before the problematic commit *and* only conditionally scheduling musb->irq_work resolves the regression: $ ping 192.168.0.100 ... 64 packets transmitted, 64 received, 0% packet loss, time 64475ms Fixes: 92af4fc6ec33 ("usb: musb: Fix suspend with devices connected for a64") Cc: stable@xxxxxxxxxxxxxxx Tested-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> Tested-by: Drew Fustini <drew@xxxxxxxxxxxxxxx> Acked-by: Tony Lindgren <tony@xxxxxxxxxxx> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20210528140446.278076-1-thomas.petazzoni@xxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/musb/musb_core.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/usb/musb/musb_core.c +++ b/drivers/usb/musb/musb_core.c @@ -2009,9 +2009,8 @@ static void musb_pm_runtime_check_sessio schedule_delayed_work(&musb->irq_work, msecs_to_jiffies(1000)); musb->quirk_retries--; - break; } - fallthrough; + break; case MUSB_QUIRK_B_INVALID_VBUS_91: if (musb->quirk_retries && !musb->flush_irq_work) { musb_dbg(musb, Patches currently in stable-queue which might be from thomas.petazzoni@xxxxxxxxxxx are queue-5.10/usb-musb-fix-musb_quirk_b_disconnect_99-handling.patch