Re: [PATCH] hw/net/can/sja1000: fix bug for single acceptance filer and standard frame

[Bernhard Beschow]

Typo in commit subject: s/filer/filter/

Am 14. Dezember 2023 10:46:23 UTC schrieb Pavel Pisa <pisa@fel.cvut.cz>:
>From: Pavel Pisa <pisa@cmp.felk.cvut.cz>
>
>A CAN sja1000 standard frame filter mask has been computed and applied
>incorrectly for standard frames when single Acceptance Filter Mode
>(MOD_AFM = 1) has been selected. The problem has not been found
>by Linux kernel testing because it uses dual filter mode (MOD_AFM = 0)
>and leaves falters fully open.
>
>The problem has been noticed by Grant Ramsay when testing with Zephyr
>RTOS which uses single filter mode.
>
>Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
>Reported-by: Grant Ramsay <gramsay@enphaseenergy.com>
>---
> hw/net/can/can_sja1000.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/hw/net/can/can_sja1000.c b/hw/net/can/can_sja1000.c
>index 73201f9139..575df7d2f8 100644
>--- a/hw/net/can/can_sja1000.c
>+++ b/hw/net/can/can_sja1000.c
>@@ -108,7 +108,7 @@ void can_sja_single_filter(struct qemu_can_filter *filter,
>         }
> 
>         filter->can_mask = (uint32_t)amr[0] << 3;
>-        filter->can_mask |= (uint32_t)amr[1] << 5;
>+        filter->can_mask |= (uint32_t)amr[1] >> 5;
>         filter->can_mask = ~filter->can_mask & QEMU_CAN_SFF_MASK;
>         if (!(amr[1] & 0x10)) {
>             filter->can_mask |= QEMU_CAN_RTR_FLAG;