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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: "Jiangong.Han" <jiangong.han@windriver.com>,
	gregkh@linuxfoundation.org, surban@surban.net,
	eeodqql09@gmail.com, kees@kernel.org, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] usb: gadget: dummy_hcd: fix IRQs-disabled violation in dummy_timer()
Date: Fri, 17 Jul 2026 10:34:23 +0200	[thread overview]
Message-ID: <20260717083423.NViVto15@linutronix.de> (raw)
In-Reply-To: <17c672c6-bac3-456a-895f-d5406624a3fd@rowland.harvard.edu>

On 2026-07-15 22:15:52 [-0400], Alan Stern wrote:
> This is not the right way to solve the problem observed in carl9170.  It 
> is documented that usb_hcd_giveback_urb() runs in atomic context, and 
> drivers' completion handlers should not expect to be called with 
> interrupts enabled.  The problem lies in carl9170_get_queued_skb(); 
> that's where it needs to be fixed.

I guess we don't see this that often because the widely used HCDs have
HCD_BH set.
I sort of think that we already did have this conversation about
having unlock+lock with irq and not skipping it. But yes, while this
would solve the problem _here_ we would still have the same warning on
OHCI.

Take a look at other drivers in drivers/net/usb/, they delay their doing
to napi/ workqueue/ tasklet.

> Alan Stern

Sebastian

      reply	other threads:[~2026-07-17  8:34 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-16  2:07 Jiangong.Han
2026-07-16  2:15 ` Alan Stern
2026-07-17  8:34   ` Sebastian Andrzej Siewior [this message]

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