From: Marc Kleine-Budde <mkl@pengutronix.de>
To: Torin Cooper-Bennun <torin@maxiluxsystems.com>
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 10:16:54 +0100 [thread overview]
Message-ID: <59ad45a4-1404-4622-5f75-3ea08aa15287@pengutronix.de> (raw)
In-Reply-To: <20210308091130.23736cyh7euvwxse@bigthink>
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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.
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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next prev parent reply other threads:[~2021-03-08 9:18 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 [this message]
2021-03-08 10:31 ` Torin Cooper-Bennun
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