Re: [PATCH net-next] net: Correct wrong BH disable in hard-interrupt.

On Wed, 23 Feb 2022 09:05:43 +0100 Sebastian Andrzej Siewior wrote:

On 2022-02-16 18:50:46 [+0100], Sebastian Andrzej Siewior wrote:

quoted

I missed the obvious case where netif_ix() is invoked from hard-IRQ
context.

Disabling bottom halves is only needed in process context. This ensures
that the code remains on the current CPU and that the soft-interrupts
are processed at local_bh_enable() time.
In hard- and soft-interrupt context this is already the case and the
soft-interrupts will be processed once the context is left (at irq-exit
time).

Disable bottom halves if neither hard-interrupts nor soft-interrupts are
disabled. Update the kernel-doc, mention that interrupts must be enabled
if invoked from process context.

Fixes: baebdf48c3600 ("net: dev: Makes sure netif_rx() can be invoked in any context.")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>  

This patch is marked as "Changes Requested" in patchwork. Could someone
please explain?
The USB/dwc3 fallout reported by Marek was addressed in 
   usb: dwc3: gadget: Let the interrupt handler disable bottom halves.
   https://lore.kernel.org/r/Yg/YPejVQH3KkRVd@linutronix.de

and is not a shortcoming in this patch but a problem in dwc3 that was
just noticed.

Unclear, let me apply it now.