[Sound-open-firmware] Commit c80270e7e49 (" ipc: structures should all be aligned on 4 bytes") causes issues on i.MX8

[Girdwood, Liam R]

On Tue, 2021-05-11 at 15:20 +0000, Daniel Baluta wrote:
> > It looks like the uint64_t on the sof_ipc_stream_position are not
> > aligned on 8 bytes (with the packing, there are 7 * uint32_t before
> > them) and the ARM compiler is expecting a 8 byte alingment for
> > uint64 ?
> 
> > I'm not sure why this is showing up now as the "packed" attribute
> > would
> > force the uint64_t to be aligned on 4 bytes instead of 8 here.
> 
> > Btw, have you tried setting aligned(8) here ? or tried removing the
> > aligned(4) for stream_posn ?
> 
> I have tried setting aligned(4) on the Linux kernel header:
> 
> --- a/include/sound/sof/stream.h+++ b/include/sound/sof/stream.h
> @@ -143,6 +143,6 @@ struct sof_ipc_stream_posn {
>         uint64_t timestamp;     /**< system time stamp */
>         uint32_t xrun_comp_id;  /**< comp ID of XRUN component */
>         int32_t xrun_size;      /**< XRUN size in bytes */
> -}  __packed;
> +}  __packed __aligned(4);
>  
> It works fine with this. 
> 

Ok, this must be an ARM64 difference and I assume you have a kernel fix
brewing ?. 

Intention on FW side was to use only the L32 and S32 calls and not
cater for any unaligned load/stores (with their extra baggage). 

Liam

> 

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