Re: [PATCH] net: wan: fsl_ucc_hdlc: allocate enough MURAM for HDLC PRAM

["Christophe Leroy (CS GROUP)" <chleroy@kernel.org>]

Le 03/08/2026 à 14:58, Matevz Langus a écrit :
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> 
> More MURAM needs to be allocated than just sizeof(struct ucc_hdlc_param).
> We have noticed MURAM corruption outside of struct ucc_hdlc_param. It was
> caused by QE UCC HDLC microcode. NXP QEIWRM.pdf Rev.9 05/2018 chapter
> 14.2.2.1 HDLC Parameter RAM says 0x6c-0x100 Reserved.
> Even looking into QE UCC HDLC microcode source code reveals it actually
> stores data beyond 0x6c.
> 
> Tested on LS1043A, T1040 and MPC8569 boards running UCC in HDLC mode on kernel 6.12.
> 
> Signed-off-by: Matevz Langus <matevz.langus@borea.si>

Same in MPC8323 reference manual, it is marked "reserved" until offset 0x100

Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>



> ---
>   drivers/net/wan/fsl_ucc_hdlc.h | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/wan/fsl_ucc_hdlc.h b/drivers/net/wan/fsl_ucc_hdlc.h
> index 71d5ad0a7b98..e170d3ac9116 100644
> --- a/drivers/net/wan/fsl_ucc_hdlc.h
> +++ b/drivers/net/wan/fsl_ucc_hdlc.h
> @@ -60,6 +60,7 @@ struct ucc_hdlc_param {
>    __be16 haddr4;
>    __be16 ts_tmp;
>    __be16 tmp_mb;
> + __u8 reserved[148];
>   };
>     struct ucc_hdlc_private {
> --  2.34.1
> 
>