From: "Cunhao Lu" <1579567540@qq.com>
To: sashiko-reviews <sashiko-reviews@lists.linux.dev>
Cc: linux-can <linux-can@vger.kernel.org>,
"Marc Kleine-Budde" <mkl@pengutronix.de>,
"Oliver Hartkopp" <socketcan@hartkopp.net>,
"Vincent Mailhol" <mailhol@kernel.org>,
"Oleksij Rempel" <o.rempel@pengutronix.de>
Subject: Re: [PATCH net v5 3/6] can: rockchip_canfd: cancel bus-off restart before closing the device
Date: Thu, 15 Oct 2026 18:13:31 +0800 [thread overview]
Message-ID: <tencent_8C34600511CC8FB1699A864BE621016BC405@qq.com> (raw)
In-Reply-To: <sashiko-outbox-172613@kernel.org>
Hi,
> [Severity: High]
> Does rkcanfd_stop() also need a readback flush after disabling hardware
> interrupts, similar to the one added above in rkcanfd_set_mode()?
>
> Without a readback flush before the subsequent free_irq() call, if the
> shared IRQ line receives an interrupt before the posted write reaches
> the bus, the CPU could receive the interrupt after the handler has been
> deregistered. Could this cause an unhandled interrupt storm that disables
> the shared IRQ line entirely?
The missing readback in rkcanfd_stop() is a pre-existing issue,
independent of the restart/close race addressed by this patch. The
interrupt-mask write followed by free_irq(), without a readback, has
been present since ff60bfbaf67f ("can: rockchip_canfd: add driver for
Rockchip CAN-FD controller"). This patch does not change that sequence.
I will leave this issue out of the current series. When I have time,
I will follow up with a separate patch to fix it.
Regards,
Cunhao Lu
next prev parent reply other threads:[~2026-10-15 10:13 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-15 9:45 [PATCH net v5 0/6] can: fix bus-off restart and device close races Cunhao Lu via B4 Relay
2026-10-15 9:45 ` [PATCH net v5 1/6] can: dev: prevent bus-off recovery when the interface is not running Cunhao Lu via B4 Relay
2026-10-15 9:56 ` sashiko-bot
2026-10-15 10:22 ` Cunhao Lu
2026-10-15 9:45 ` [PATCH net v5 2/6] can: dev: add close_candev_cancel_restart_sync() Cunhao Lu via B4 Relay
2026-10-15 9:45 ` [PATCH net v5 3/6] can: rockchip_canfd: cancel bus-off restart before closing the device Cunhao Lu via B4 Relay
2026-10-15 9:57 ` sashiko-bot
2026-10-15 10:13 ` Cunhao Lu [this message]
2026-10-15 9:45 ` [PATCH net v5 4/6] can: rockchip_canfd: prevent timestamp work from rearming after bus-off Cunhao Lu via B4 Relay
2026-10-15 9:45 ` [PATCH net v5 5/6] can: rockchip_canfd: serialize TX with bus-off and restart Cunhao Lu via B4 Relay
2026-10-15 9:45 ` [PATCH net v5 6/6] can: rockchip_canfd: serialize timecounter timestamp conversion Cunhao Lu via B4 Relay
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