Re: [PATCH v6 0/4] can: esd: add support for esd GmbH PCIe/402 CAN interface

From: Marc Kleine-Budde
Date: Wed Feb 02 2022 - 07:21:47 EST


On 01.12.2021 23:03:24, Stefan Mätje wrote:
> The purpose of this patch is to introduce a new CAN driver to support
> the esd GmbH 402 family of CAN interface boards. The hardware design
> is based on a CAN controller implemented in a FPGA attached to a
> PCIe link.
>
> More information on these boards can be found following the links
> included in the commit message.
>
> This patch supports all boards but will operate the CAN-FD capable
> boards only in Classic-CAN mode. The CAN-FD support will be added
> when the initial patch has stabilized.
>
> The patch is reuses the previous work of my former colleague:
> Link: https://lore.kernel.org/linux-can/1426592308-23817-1-git-send-email-thomas.koerper@xxxxxx/
>
> *Note*: scripts/checkpatch.pl still emits the following warnings:
> - esd_402_pci-core.c:270: Possible unnecessary 'out of memory' message
> This error message is there to tell the user that the DMA allocation
> failed and not an allocation for normal kernel memory.
> - esdacc.h:255: The irq_cnt pointer is still declared volatile and
> this has a reason and is explained in detail in the header
> referencing the exception noted in volatile-considered-harmful.rst.

I think you can use READ_ONCE() instead of the volatile.

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 |

Attachment: signature.asc
Description: PGP signature