From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Alexander Aring <alex.aring@gmail.com>
Cc: Stefan Schmidt <stefan@datenfreihafen.org>,
linux-wpan - ML <linux-wpan@vger.kernel.org>,
"open list:NETWORKING [GENERAL]" <netdev@vger.kernel.org>,
"linux-wireless@vger.kernel.org Wireless"
<linux-wireless@vger.kernel.org>,
David Girault <david.girault@qorvo.com>,
Romuald Despres <romuald.despres@qorvo.com>,
Frederic Blain <frederic.blain@qorvo.com>,
Nicolas Schodet <nico@ni.fr.eu.org>,
Michael Hennerich <michael.hennerich@analog.com>,
Jakub Kicinski <kuba@kernel.org>,
Varka Bhadram <varkabhadram@gmail.com>,
Xue Liu <liuxuenetmail@gmail.com>, Alan Ott <alan@signal11.us>,
Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Subject: Re: [PATCH v3 07/41] net: ieee802154: mcr20a: Fix lifs/sifs periods
Date: Tue, 18 Jan 2022 19:20:13 +0100 [thread overview]
Message-ID: <20220118192013.46c42f82@xps13> (raw)
In-Reply-To: <CAB_54W5_XoTk=DzMmm33csrEKe3m97KnNWnktRiyJsk7vfxO6w@mail.gmail.com>
Hi Alexander,
alex.aring@gmail.com wrote on Mon, 17 Jan 2022 17:52:10 -0500:
> Hi,
>
> On Mon, 17 Jan 2022 at 06:54, Miquel Raynal <miquel.raynal@bootlin.com> wrote:
> >
> > These periods are expressed in time units (microseconds) while 40 and 12
> > are the number of symbol durations these periods will last. We need to
> > multiply them both with phy->symbol_duration in order to get these
> > values in microseconds.
> >
> > Fixes: 8c6ad9cc5157 ("ieee802154: Add NXP MCR20A IEEE 802.15.4 transceiver driver")
> > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> > ---
> > drivers/net/ieee802154/mcr20a.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/ieee802154/mcr20a.c b/drivers/net/ieee802154/mcr20a.c
> > index f0eb2d3b1c4e..e2c249aef430 100644
> > --- a/drivers/net/ieee802154/mcr20a.c
> > +++ b/drivers/net/ieee802154/mcr20a.c
> > @@ -976,8 +976,8 @@ static void mcr20a_hw_setup(struct mcr20a_local *lp)
> > dev_dbg(printdev(lp), "%s\n", __func__);
> >
> > phy->symbol_duration = 16;
> > - phy->lifs_period = 40;
> > - phy->sifs_period = 12;
> > + phy->lifs_period = 40 * phy->symbol_duration;
> > + phy->sifs_period = 12 * phy->symbol_duration;
>
> I thought we do that now in register_hw(). Why does this patch exist?
The lifs and sifs period are wrong.
Fixing this silently by generalizing the calculation is simply wrong. I
feel we need to do this in order:
1- Fix the period because it is wrong.
2- Now that the period is set to a valid value and the core is able to
do the same operation and set the variables to an identical content,
we can drop these lines from the driver.
#2 being a mechanical change, doing it without #1 means that something
that appears harmless actually changes the behavior of the driver. We
generally try to avoid that, no?
Thanks,
Miquèl
next prev parent reply other threads:[~2022-01-18 18:20 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-17 11:53 [PATCH v3 00/41] IEEE 802.15.4 scan support Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 01/41] MAINTAINERS: Remove Harry Morris bouncing address Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 02/41] net: ieee802154: hwsim: Ensure proper channel selection at probe time Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 03/41] net: ieee802154: hwsim: Ensure frame checksum are valid Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 04/41] net: ieee802154: Use the IEEE802154_MAX_PAGE define when relevant Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 05/41] net: ieee802154: Improve the way supported channels are declared Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 06/41] net: ieee802154: Give more details to the core about the channel configurations Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 07/41] net: ieee802154: mcr20a: Fix lifs/sifs periods Miquel Raynal
2022-01-17 22:52 ` Alexander Aring
2022-01-18 18:20 ` Miquel Raynal [this message]
2022-01-18 22:53 ` Alexander Aring
2022-01-17 11:54 ` [PATCH v3 08/41] net: mac802154: Convert the symbol duration into nanoseconds Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 09/41] net: mac802154: Set the symbol duration automatically Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 10/41] net: ieee802154: Drop duration settings when the core does it already Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 11/41] net: ieee802154: Move IEEE 802.15.4 Kconfig main entry Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 12/41] net: mac802154: Include the softMAC stack inside the IEEE 802.15.4 menu Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 13/41] net: ieee802154: Move the address structure earlier Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 14/41] net: ieee802154: Add a kernel doc header to the ieee802154_addr structure Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 15/41] net: ieee802154: Return meaningful error codes from the netlink helpers Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 16/41] net: mac802154: Explain the use of ieee802154_wake/stop_queue() Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 17/41] net: ieee802154: at86rf230: Call the complete helper when a transmission is over Miquel Raynal
2022-01-17 22:58 ` Alexander Aring
2022-01-18 0:34 ` Alexander Aring
2022-01-18 0:36 ` Alexander Aring
2022-01-18 18:22 ` Miquel Raynal
2022-01-19 22:45 ` Miquel Raynal
2022-01-19 22:56 ` Miquel Raynal
2022-01-19 23:34 ` Alexander Aring
2022-01-20 0:19 ` Alexander Aring
2022-01-17 11:54 ` [PATCH v3 18/41] net: ieee802154: atusb: " Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 19/41] net: ieee802154: ca8210: " Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 20/41] net: mac802154: Stop exporting ieee802154_wake/stop_queue() Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 21/41] net: mac802154: Rename the synchronous xmit worker Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 22/41] net: mac802154: Rename the main tx_work struct Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 23/41] net: mac802154: Follow the count of ongoing transmissions Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 24/41] net: mac802154: Hold the transmit queue when relevant Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 25/41] net: mac802154: Create a hot tx path Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 26/41] net: mac802154: Add a warning in the hot path Miquel Raynal
2022-01-17 23:14 ` Alexander Aring
2022-01-18 18:20 ` Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 27/41] net: mac802154: Introduce a tx queue flushing mechanism Miquel Raynal
2022-01-17 22:43 ` Alexander Aring
2022-01-18 18:14 ` Miquel Raynal
2022-01-18 23:16 ` Alexander Aring
2022-01-17 11:54 ` [PATCH v3 28/41] net: mac802154: Introduce a synchronous API for MLME commands Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 29/41] net: ieee802154: Add support for internal PAN management Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 30/41] net: ieee802154: Define a beacon frame header Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 31/41] net: ieee802154: Define frame types Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 32/41] net: ieee802154: Add support for scanning requests Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 33/41] net: mac802154: Handle scan requests Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 34/41] net: ieee802154: Full PAN management Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 35/41] net: ieee802154: Add beacons support Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 36/41] net: mac802154: Handle beacons requests Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 37/41] net: ieee802154: Trace the registration of new PANs Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 38/41] net: mac802154: Add support for active scans Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 39/41] net: mac802154: Add support for processing beacon requests Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 40/41] net: ieee802154: Handle limited devices with only datagram support Miquel Raynal
2022-01-17 11:54 ` [PATCH v3 41/41] net: ieee802154: ca8210: Flag the driver as being limited Miquel Raynal
2022-01-17 23:02 ` [PATCH v3 00/41] IEEE 802.15.4 scan support Alexander Aring
2022-01-18 10:40 ` Miquel Raynal
2022-01-18 23:12 ` Alexander Aring
2022-01-20 0:24 ` Miquel Raynal
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