From: Torin Cooper-Bennun <torin@maxiluxsystems.com>
To: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: linux-can@vger.kernel.org, Pankaj Sharma <pankj.sharma@samsung.com>
Subject: Re: [PATCH 3/3] can: m_can: fix RX path: use rx-offload to ensure skbs are sent from softirq context
Date: Mon, 8 Mar 2021 10:31:17 +0000 [thread overview]
Message-ID: <20210308103117.o772ve7gjfrpalaq@bigthink> (raw)
In-Reply-To: <59ad45a4-1404-4622-5f75-3ea08aa15287@pengutronix.de>
On Mon, Mar 08, 2021 at 10:16:54AM +0100, Marc Kleine-Budde wrote:
> On 3/8/21 10:11 AM, Torin Cooper-Bennun wrote:
> > On Fri, Mar 05, 2021 at 11:29:57PM +0100, Marc Kleine-Budde wrote:
> >> On 05.03.2021 17:20:15, Torin Cooper-Bennun wrote:
> >>> For peripheral devices, m_can sent skbs directly from a threaded irq
> >>> instead of from a softirq context. This patch transitions the driver to
> >>> use the rx-offload helper, ensuring the skbs are sent from the correct
> >>> context, with h/w timestamping to ensure correct ordering.
> >>
> >> I think you beak the non-peripheral drivers here. They already have a
> >> NAPI function m_can_poll(). It makes no sense and doesn't work, if you
> >> do the RX in NAPI and then queue to rx-offload, which then needs to run
> >> from NAPI again. But it cannot as m_can_poll is the NAPI function.
> >>
> >> For peripherals it works, as you do the RX in the threaded IRQ, queue to
> >> rx-offload, which then schedules a NAPI, to push the CAN frames into the
> >> networking stack.
> >
> > Understood, I will make the skb handling conditional on
> > cdev->is_peripheral and retain netif_receive_skb and can_get_echo_skb
> > usage for non-peripherals as before.
>
> Not beautify, but should make the tcan driver work at least.
Submitted v2 of patches, hopefully hit a good compromise :)
--
Regards,
Torin Cooper-Bennun
Software Engineer | maxiluxsystems.com
prev parent reply other threads:[~2021-03-08 10:32 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-05 17:20 [PATCH 0/3] can: m_can: stabilise peripheral m_can RX and TX Torin Cooper-Bennun
2021-03-05 17:20 ` [PATCH 1/3] can: m_can: add infrastructure for internal timestamps Torin Cooper-Bennun
2021-03-05 21:28 ` Marc Kleine-Budde
2021-03-05 17:20 ` [PATCH 2/3] can: m_can: m_can_chip_config(): enable and configure " Torin Cooper-Bennun
2021-03-05 21:34 ` Marc Kleine-Budde
2021-03-08 9:09 ` Torin Cooper-Bennun
2021-03-05 17:20 ` [PATCH 3/3] can: m_can: fix RX path: use rx-offload to ensure skbs are sent from softirq context Torin Cooper-Bennun
2021-03-05 22:29 ` Marc Kleine-Budde
2021-03-08 9:11 ` Torin Cooper-Bennun
2021-03-08 9:16 ` Marc Kleine-Budde
2021-03-08 10:31 ` Torin Cooper-Bennun [this message]
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