From: Dan Carpenter <dan.carpenter@oracle.com>
To: Coiby Xu <coiby.xu@gmail.com>
Cc: linux-staging@lists.linux.dev, netdev@vger.kernel.org,
Benjamin Poirier <benjamin.poirier@gmail.com>,
Shung-Hsi Yu <shung-hsi.yu@suse.com>,
Manish Chopra <manishc@marvell.com>,
"supporter:QLOGIC QLGE 10Gb ETHERNET DRIVER"
<GR-Linux-NIC-Dev@marvell.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: [RFC 16/19] staging: qlge: remove deadcode in qlge_build_rx_skb
Date: Mon, 28 Jun 2021 09:46:45 +0300 [thread overview]
Message-ID: <20210628064645.GK2040@kadam> (raw)
In-Reply-To: <20210627105349.pflw2r2b4qus64kf@Rk>
On Sun, Jun 27, 2021 at 06:53:49PM +0800, Coiby Xu wrote:
> On Thu, Jun 24, 2021 at 03:49:26PM +0300, Dan Carpenter wrote:
> > On Thu, Jun 24, 2021 at 07:25:00PM +0800, Coiby Xu wrote:
> > > On Tue, Jun 22, 2021 at 10:29:39AM +0300, Dan Carpenter wrote:
> > > > On Mon, Jun 21, 2021 at 09:48:59PM +0800, Coiby Xu wrote:
> > > > > This part of code is for the case that "the headers and data are in
> > > > > a single large buffer". However, qlge_process_mac_split_rx_intr is for
> > > > > handling packets that packets underwent head splitting. In reality, with
> > > > > jumbo frame enabled, the part of code couldn't be reached regardless of
> > > > > the packet size when ping the NIC.
> > > > >
> > > >
> > > > This commit message is a bit confusing. We're just deleting the else
> > > > statement. Once I knew that then it was easy enough to review
> > > > qlge_process_mac_rx_intr() and see that if if
> > > > ib_mac_rsp->flags3 & IB_MAC_IOCB_RSP_DL is set then
> > > > ib_mac_rsp->flags4 & IB_MAC_IOCB_RSP_HV must be set.
> > >
> > > Do you suggest moving to upper if, i.e.
> > >
> > > } else if (ib_mac_rsp->flags3 & IB_MAC_IOCB_RSP_DL && ib_mac_rsp->flags4 & IB_MAC_IOCB_RSP_HS) {
> > >
> > > and then deleting the else statement?
> > >
> >
> > I have a rule that when people whinge about commit messages they should
> > write a better one themselves, but I have violated my own rule. Sorry.
> > Here is my suggestion:
> >
> > If the "ib_mac_rsp->flags3 & IB_MAC_IOCB_RSP_DL" condition is true
> > then we know that "ib_mac_rsp->flags4 & IB_MAC_IOCB_RSP_HS" must be
> > true as well. Thus, we can remove that condition and delete the
> > else statement which is dead code.
> >
> > (Originally this code was for the case that "the headers and data are
> > in a single large buffer". However, qlge_process_mac_split_rx_intr
> > is for handling packets that packets underwent head splitting).
>
> Thanks for sharing your commit message! Now I see what you mean. But I'm
> not sure if "ib_mac_rsp->flags4 & IB_MAC_IOCB_RSP_HS" is true when
> "ib_mac_rsp->flags3 & IB_MAC_IOCB_RSP_DL" is true.
Well... It is true. qlge_process_mac_split_rx_intr() is only called
when "->flags4 & IB_MAC_IOCB_RSP_HS" is true or when
"->flags3 & IB_MAC_IOCB_RSP_DL" is false.
To me the fact that it's clearly dead code, helps me to verify that the
patch doesn't change behavior. Anyway, "this part of code" was a bit
vague and it took me a while to figure out the patch deletes the else
statement.
regards,
dan carpenter
next prev parent reply other threads:[~2021-06-28 6:47 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-21 13:48 [RFC 00/19] Improve the qlge driver based on drivers/staging/qlge/TODO Coiby Xu
2021-06-21 13:48 ` [RFC 01/19] staging: qlge: fix incorrect truesize accounting Coiby Xu
2021-06-21 14:10 ` Dan Carpenter
2021-06-22 11:36 ` Coiby Xu
2021-06-23 4:55 ` Benjamin Poirier
2021-06-24 11:47 ` Coiby Xu
2021-06-28 0:14 ` Coiby Xu
2021-06-21 13:48 ` [RFC 02/19] staging: qlge: change LARGE_BUFFER_MAX_SIZE to 4096 Coiby Xu
2021-06-21 13:48 ` [RFC 03/19] staging: qlge: alloc skb with only enough room for header when data is put in the fragments Coiby Xu
2021-06-21 13:48 ` [RFC 04/19] staging: qlge: add qlge_* prefix to avoid namespace clashes Coiby Xu
2021-06-22 7:55 ` Benjamin Poirier
2021-06-24 11:34 ` Coiby Xu
2021-06-21 13:48 ` [RFC 05/19] staging: qlge: rename rx to completion queue and seperate rx_ring from completion queue Coiby Xu
2021-06-21 13:48 ` [RFC 06/19] staging: qlge: disable flow control by default Coiby Xu
2021-06-22 7:49 ` Benjamin Poirier
2021-06-24 11:33 ` Coiby Xu
2021-06-21 13:48 ` [RFC 07/19] staging: qlge: remove the TODO item of unnecessary memset 0 Coiby Xu
2021-06-21 13:48 ` [RFC 08/19] staging: qlge: reorder members of qlge_adapter for optimization Coiby Xu
2021-06-21 13:48 ` [RFC 09/19] staging: qlge: remove the TODO item of reorder struct Coiby Xu
2021-06-21 13:48 ` [RFC 10/19] staging: qlge: remove the TODO item of avoid legacy/deprecated apis Coiby Xu
2021-06-21 13:48 ` [RFC 11/19] staging: qlge: the number of pages to contain a buffer queue is constant Coiby Xu
2021-06-21 13:48 ` [RFC 12/19] staging: qlge: rewrite do while loops as for loops in qlge_start_rx_ring Coiby Xu
2021-06-22 7:45 ` Benjamin Poirier
2021-06-24 11:56 ` Coiby Xu
2021-06-21 13:48 ` [RFC 13/19] staging: qlge: rewrite do while loop as for loop in qlge_sem_spinlock Coiby Xu
2021-06-22 7:20 ` Dan Carpenter
2021-06-24 11:22 ` Coiby Xu
2021-06-30 10:58 ` Joe Perches
2021-06-30 23:33 ` Coiby Xu
2021-07-01 4:35 ` Joe Perches
2021-07-02 23:56 ` Coiby Xu
2021-06-21 13:48 ` [RFC 14/19] staging: qlge: rewrite do while loop as for loop in qlge_refill_bq Coiby Xu
2021-06-21 13:48 ` [RFC 15/19] staging: qlge: remove the TODO item about rewriting while loops as simple for loops Coiby Xu
2021-06-21 13:48 ` [RFC 16/19] staging: qlge: remove deadcode in qlge_build_rx_skb Coiby Xu
2021-06-22 7:29 ` Dan Carpenter
2021-06-24 11:25 ` Coiby Xu
2021-06-24 12:49 ` Dan Carpenter
2021-06-27 10:53 ` Coiby Xu
2021-06-28 6:46 ` Dan Carpenter [this message]
2021-06-29 13:35 ` Coiby Xu
2021-06-29 14:22 ` Dan Carpenter
2021-06-30 23:19 ` Coiby Xu
2021-06-21 13:49 ` [RFC 17/19] staging: qlge: fix weird line wrapping Coiby Xu
2021-06-22 8:46 ` Dan Carpenter
2021-06-24 11:55 ` Coiby Xu
2021-06-21 13:49 ` [RFC 18/19] staging: qlge: fix two indentation issues Coiby Xu
2021-06-21 13:49 ` [RFC 19/19] staging: qlge: remove TODO item of unnecessary runtime checks Coiby Xu
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