Re: [patch 12/14] PCI: hv: Use tasklet_disable_in_atomic()

Bjorn Helgaas
2021-03-09T22:18:48Z

On Tue, Mar 09, 2021 at 09:42:15AM +0100, Thomas Gleixner wrote:
> From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
>
> The hv_compose_msi_msg() callback in irq_chip::irq_compose_msi_msg is
> invoked via irq_chip_compose_msi_msg(), which itself is always invoked from
> atomic contexts from the guts of the interrupt core code.
>
> There is no way to change this w/o rewriting the whole driver, so use
> tasklet_disable_in_atomic() which allows to make tasklet_disable()
> sleepable once the remaining atomic users are addressed.
>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: "K. Y. Srinivasan" <kys@microsoft.com>
> Cc: Haiyang Zhang <haiyangz@microsoft.com>
> Cc: Stephen Hemminger <sthemmin@microsoft.com>
> Cc: Wei Liu <wei.liu@kernel.org>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: linux-hyperv@vger.kernel.org
> Cc: linux-pci@vger.kernel.org

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

It'd be ideal if you could merge this as a group. Let me know if you
want me to do anything else.

> ---
> drivers/pci/controller/pci-hyperv.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -1458,7 +1458,7 @@ static void hv_compose_msi_msg(struct ir
> * Prevents hv_pci_onchannelcallback() from running concurrently
> * in the tasklet.
> */
> - tasklet_disable(&channel->callback_event);
> + tasklet_disable_in_atomic(&channel->callback_event);
>
> /*
> * Since this function is called with IRQ locks held, can't
>