Re: [patch V2 02/13] USB: serial: keyspan_pda: Replace in_interrupt() usage
From: Johan Hovold <johan@kernel.org>
Date: 2020-10-27 08:16:56
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linux-omap, linux-samsung-soc, linux-usb, lkml
On Mon, Oct 26, 2020 at 01:47:53PM +0100, Sebastian Andrzej Siewior wrote:
On 2020-10-25 17:56:47 [+0100], Johan Hovold wrote:quoted
There's a ton of issues with this driver, but this is arguably making things worse. A line discipline may call write() from just about any context so we cannot rely on tty being non-NULL here (e.g. PPP).I wasn't aware of that. I've been looking at the callers each time a `tty' was passed it looked like a preemptible context (due to mutex / GFP_KERNEL) and so on.
Yeah, the default line discipline only calls in preemptible context (these days), but others do not (e.g. see ppp_async_push()). Johan _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel