Re: [edk2-devel] [PATCH v2 1/3] UsbNetworkPkg/UsbRndis: Add USB RNDIS devices support

["Michael Brown" <mcb30@ipxe.org>]

On 07/02/2023 06:21, Tinh Nguyen via groups.io wrote:
> From: Tinh Nguyen <tinhn@os.amperecomputing.com>
> Date: Tue, 7 Feb 2023 12:43:17 +0700
> Subject: [PATCH] UsbNetworkPkg: Support rate limitting
> 
> Signed-off-by: Tinh Nguyen <tinhn@os.amperecomputing.com>

Thank you for extending my patch to add the PCD support.  The overall 
patch appears still to be substantially my code: could you please credit 
it as such?

> +  if (Nic->RateLimitCredit < PcdGet32 (RateLimitingResumeTime)) {
> +    Nic->RateLimitCredit++;
> +  }

Is PcdGet32() guaranteed to be a compile-time constant?  If not, then 
it's probably a good idea to read it once upon initialisation, rather 
than once per timer interrupt handler invocation.

> +  if ((Nic->RateLimitCredit == 0) && (PcdGetBool (EnableRateLimiting))) {
> +    return PXE_STATCODE_NO_DATA;
> +  }

Again: unless PcdGetBool() is guaranteed to be a compile-time constant, 
then it's probably best to avoid reading it on every call to Receive().

(Sorry, I've never been clear on how the PCD mechanism works, so I'm not 
sure whether or not there is any runtime overhead from reading them.)

Thanks,

Michael