Re: [PATCH v2 1/2] accel/qaic: Add support for periodic timesync

[Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>]

On Mon, Oct 16, 2023 at 11:01:13AM -0600, Jeffrey Hugo wrote:
> From: Ajit Pal Singh <quic_ajitpals@quicinc.com>
> 
> Device and Host have a time synchronization mechanism that happens once
> during boot when device is in SBL mode. After that, in mission-mode there
> is no timesync. In an experiment after continuous operation, device time
> drifted w.r.t. host by approximately 3 seconds per day. This drift leads
> to mismatch in timestamp of device and Host logs. To correct this
> implement periodic timesync in driver. This timesync is carried out via
> QAIC_TIMESYNC_PERIODIC MHI channel.
> 
> Signed-off-by: Ajit Pal Singh <quic_ajitpals@quicinc.com>
> Signed-off-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@quicinc.com>
> Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
> Reviewed-by: Carl Vanderlip <quic_carlv@quicinc.com>
> Reviewed-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@quicinc.com>
> Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>

> @@ -586,8 +587,16 @@ static int __init qaic_init(void)
>  		goto free_pci;
>  	}
>  
> +	ret = qaic_timesync_init();
> +	if (ret) {
> +		pr_debug("qaic: qaic_timesync_init failed %d\n", ret);
> +		goto free_mhi;
I would print at error level here. Or if timesync is optional do not error exit. 

> +#ifdef readq
> +static u64 read_qtimer(const volatile void __iomem *addr)
> +{
> +	return readq(addr);
> +}
> +#else
> +static u64 read_qtimer(const volatile void __iomem *addr)
> +{
> +	u64 low, high;
> +
> +	low = readl(addr);
> +	high = readl(addr + sizeof(u32));
> +	return low | (high << 32);
> +}
If that's only for compile on 32-bit PowerPC, I think would be better
to limit supported architectures on Kconfig. 

Regards
Stanislaw