netdev - Re: [PATCH net 1/2] bnxt_en: Mask the bd

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Message-ID: <20250324141229.153b3adf@kernel.org>
Date: Mon, 24 Mar 2025 14:12:29 -0700
From: Jakub Kicinski <kuba@...nel.org>
To: Michael Chan <michael.chan@...adcom.com>
Cc: davem@...emloft.net, netdev@...r.kernel.org, edumazet@...gle.com,
 pabeni@...hat.com, andrew+netdev@...n.ch, pavan.chebbi@...adcom.com,
 andrew.gospodarek@...adcom.com, osk@...gle.com, Kalesh AP
 <kalesh-anakkur.purayil@...adcom.com>, Somnath Kotur
 <somnath.kotur@...adcom.com>
Subject: Re: [PATCH net 1/2] bnxt_en: Mask the bd_cnt field in the TX BD
 properly

On Fri, 21 Mar 2025 14:16:38 -0700 Michael Chan wrote:
> The bd_cnt field in the TX BD specifies the total number of BDs for
> the TX packet.  The bd_cnt field has 5 bits and the maximum number
> supported is 32 with the value 0.
> 
> CONFIG_MAX_SKB_FRAGS can be modified and the total number of SKB
> fragments can approach or exceed the maximum supported by the chip.
> Add a macro to properly mask the bd_cnt field so that the value 32
> will be properly masked and set to 0 in the bd_cnd field.
> 
> Without this patch, the out-of-range bd_cnt value will corrupt the
> TX BD and may cause TX timeout.
> 
> The next patch will check for values exceeding 32.

Could you clarify how this patch improves things, exactly?
Patch 2/2 looks like the real fix, silently truncating 
the number of frags does not seem to make anything correct..
-- 
pw-bot: cr