Subject: Re: [PATCH iwl-net v2] igb: Fix not clearing TimeSync interrupts for 82580

From: Vinicius Costa Gomes <[email-masked]>
Date: Tue, 13 Aug 2024 15:26:07 -0700

Daiwei Li <[email-masked]> writes:

> 82580 NICs have a hardware bug that makes it
> necessary to write into the TSICR (TimeSync Interrupt Cause) register
> to clear it:
> https://lore.kernel.org/all/[email-masked]/
>
> Add a conditional so only for 82580 we write into the TSICR register,
> so we don't risk losing events for other models.

Please add some information in the commit message about how to reproduce
the issue, as Paul suggested.

>
> This (partially) reverts commit ee14cc9ea19b ("igb: Fix missing time sync events").
>
> Fixes: ee14cc9ea19b ("igb: Fix missing time sync events")
> Closes: https://lore.kernel.org/intel-wired-lan/CAN0jFd1kO0MMtOh8N2Ztxn6f7vvDKp2h507sMryobkBKe=xk=[email-masked]/
> Tested-by: Daiwei Li <[email-masked]>
> Signed-off-by: Daiwei Li <[email-masked]>
> ---
>
> @Vinicius Gomes, this is my first time submitting a Linux kernel patch,
> so apologies if I missed any part of the procedure (e.g. this is
> currently on top of 6.7.12, the kernel I am running; should I be
> rebasing on inline?). Also, is there any way to annotate the patch
> to give you credit for the original change?

Your submission format looks fine. Just a couple details:
 - No need for setting in-reply-to (or something like it);
 
 - For this particular patch, you got lucky and it applies cleanly
 against current tip, but for future submissions, for intel-wired-lan
 and patches intended for the stable tree, please rebase against:

 https://git.kernel.org/pub/scm/linux/kernel/git/tnguy/net-queue.git/

For credits, you can add something like:

Suggested-by: Vinicius Costa Gomes <[email-masked]>

>
>  drivers/net/ethernet/intel/igb/igb_main.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
> index ada42ba63549..1210ddc5d81e 100644
> --- a/drivers/net/ethernet/intel/igb/igb_main.c
> +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> @@ -6986,6 +6986,16 @@ static void igb_tsync_interrupt(struct igb_adapter *adapter)
>  	struct e1000_hw *hw = &adapter->hw;
>  	u32 tsicr = rd32(E1000_TSICR);
>  	struct ptp_clock_event event;
> +	const u32 mask = (TSINTR_SYS_WRAP | E1000_TSICR_TXTS |
> +			  TSINTR_TT0 | TSINTR_TT1 |
> +			  TSINTR_AUTT0 | TSINTR_AUTT1);
> +

Please move the declaration of 'mask' up, to follow the convention, the
"reverse christmas tree" rule. Or separate the attribution from the
declaration.

> +	if (hw->mac.type == e1000_82580) {
> +		/* 82580 has a hardware bug that requires a explicit

And as pointed by Paul, "*an* explicit".

> +		 * write to clear the TimeSync interrupt cause.
> +		 */
> +		wr32(E1000_TSICR, tsicr & mask);
> +	}
>  
>  	if (tsicr & TSINTR_SYS_WRAP) {
>  		event.type = PTP_CLOCK_PPS;
> -- 
> 2.46.0.76.ge559c4bf1a-goog
>

-- 
Vinicius