From: "Jérôme Pouiller" <jerome.pouiller@silabs.com>
To: Kalle Valo <kvalo@codeaurora.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: devel@driverdev.osuosl.org, devicetree@vger.kernel.org,
"Ulf Hansson" <ulf.hansson@linaro.org>,
netdev@vger.kernel.org, linux-wireless@vger.kernel.org,
linux-kernel@vger.kernel.org, "Rob Herring" <robh+dt@kernel.org>,
linux-mmc@vger.kernel.org, "Pali Rohár" <pali@kernel.org>,
"David S . Miller" <davem@davemloft.net>
Subject: Re: [PATCH v3 09/24] wfx: add hwio.c/hwio.h
Date: Tue, 22 Dec 2020 22:02:09 +0100 [thread overview]
Message-ID: <4279510.LvFx2qVVIh@pc-42> (raw)
In-Reply-To: <X+IQRct0Zsm87H4+@kroah.com>
On Tuesday 22 December 2020 16:27:01 CET Greg Kroah-Hartman wrote:
>
> On Tue, Dec 22, 2020 at 05:10:11PM +0200, Kalle Valo wrote:
> > Jerome Pouiller <Jerome.Pouiller@silabs.com> writes:
> >
> > > +/*
> > > + * Internal helpers.
> > > + *
> > > + * About CONFIG_VMAP_STACK:
> > > + * When CONFIG_VMAP_STACK is enabled, it is not possible to run DMA on stack
> > > + * allocated data. Functions below that work with registers (aka functions
> > > + * ending with "32") automatically reallocate buffers with kmalloc. However,
> > > + * functions that work with arbitrary length buffers let's caller to handle
> > > + * memory location. In doubt, enable CONFIG_DEBUG_SG to detect badly located
> > > + * buffer.
> > > + */
> >
> > This sounds very hacky to me, I have understood that you should never
> > use stack with DMA.
>
> You should never do that because some platforms do not support it, so no
> driver should ever try to do that as they do not know what platform they
> are running on.
Yes, I have learned this rule the hard way.
There is no better way than a comment to warn the user that the argument
will be used with a DMA? A Sparse annotation, for example?
--
Jérôme Pouiller
_______________________________________________
devel mailing list
devel@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
next prev parent reply other threads:[~2020-12-22 21:35 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-04 15:51 [PATCH v3 00/24] wfx: get out from the staging area Jerome Pouiller
2020-11-04 15:51 ` [PATCH v3 01/24] mmc: sdio: add SDIO IDs for Silabs WF200 chip Jerome Pouiller
2020-12-22 15:04 ` Kalle Valo
2020-11-04 15:51 ` [PATCH v3 02/24] dt-bindings: introduce silabs,wfx.yaml Jerome Pouiller
2020-11-04 19:15 ` Rob Herring
2020-11-05 8:36 ` Jérôme Pouiller
2020-11-04 15:51 ` [PATCH v3 03/24] wfx: add Makefile/Kconfig Jerome Pouiller
2020-12-22 15:02 ` Kalle Valo
2020-12-22 21:19 ` Jérôme Pouiller
2020-12-23 5:16 ` Kalle Valo
2020-12-22 15:05 ` Kalle Valo
2020-11-04 15:51 ` [PATCH v3 04/24] wfx: add wfx.h Jerome Pouiller
2020-11-04 15:51 ` [PATCH v3 05/24] wfx: add main.c/main.h Jerome Pouiller
2020-12-22 15:07 ` Kalle Valo
2020-12-22 15:44 ` Kalle Valo
2020-12-23 12:09 ` Jérôme Pouiller
2020-11-04 15:51 ` [PATCH v3 06/24] wfx: add bus.h Jerome Pouiller
2020-11-04 15:51 ` [PATCH v3 07/24] wfx: add bus_spi.c Jerome Pouiller
2020-11-04 15:51 ` [PATCH v3 08/24] wfx: add bus_sdio.c Jerome Pouiller
2020-11-04 15:51 ` [PATCH v3 09/24] wfx: add hwio.c/hwio.h Jerome Pouiller
2020-12-22 15:10 ` Kalle Valo
2020-12-22 15:27 ` Greg Kroah-Hartman
2020-12-22 21:02 ` Jérôme Pouiller [this message]
2020-12-23 5:28 ` Kalle Valo
2021-01-04 12:34 ` Dan Carpenter
2021-01-04 12:38 ` Dan Carpenter
2021-01-04 14:48 ` Johan Hovold
2020-12-23 8:01 ` Jérôme Pouiller
2020-12-23 8:09 ` Greg Kroah-Hartman
2020-11-04 15:51 ` [PATCH v3 10/24] wfx: add fwio.c/fwio.h Jerome Pouiller
2020-11-04 15:51 ` [PATCH v3 11/24] wfx: add bh.c/bh.h Jerome Pouiller
2020-11-04 15:51 ` [PATCH v3 12/24] wfx: add hif_api_*.h Jerome Pouiller
2020-12-22 15:20 ` Kalle Valo
2020-12-22 21:05 ` Jérôme Pouiller
2020-11-04 15:51 ` [PATCH v3 13/24] wfx: add hif_tx*.c/hif_tx*.h Jerome Pouiller
2020-11-04 15:51 ` [PATCH v3 14/24] wfx: add key.c/key.h Jerome Pouiller
2020-11-04 15:51 ` [PATCH v3 15/24] wfx: add hif_rx.c/hif_rx.h Jerome Pouiller
2020-11-04 15:51 ` [PATCH v3 16/24] wfx: add data_rx.c/data_rx.h Jerome Pouiller
2020-11-04 15:52 ` [PATCH v3 17/24] wfx: add queue.c/queue.h Jerome Pouiller
2020-11-04 15:52 ` [PATCH v3 18/24] wfx: add data_tx.c/data_tx.h Jerome Pouiller
2020-12-22 15:27 ` Kalle Valo
2020-12-22 15:31 ` Kalle Valo
2020-11-04 15:52 ` [PATCH v3 19/24] wfx: add sta.c/sta.h Jerome Pouiller
2020-11-04 15:52 ` [PATCH v3 20/24] wfx: add scan.c/scan.h Jerome Pouiller
2020-11-04 15:52 ` [PATCH v3 21/24] wfx: add debug.c/debug.h Jerome Pouiller
2020-11-04 15:52 ` [PATCH v3 22/24] wfx: add traces.h Jerome Pouiller
2020-11-04 15:52 ` [PATCH v3 23/24] wfx: remove from the staging area Jerome Pouiller
2020-11-04 15:52 ` [PATCH v3 24/24] wfx: get out " Jerome Pouiller
2020-12-22 15:23 ` [PATCH v3 00/24] " Kalle Valo
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4279510.LvFx2qVVIh@pc-42 \
--to=jerome.pouiller@silabs.com \
--cc=davem@davemloft.net \
--cc=devel@driverdev.osuosl.org \
--cc=devicetree@vger.kernel.org \
--cc=gregkh@linuxfoundation.org \
--cc=kvalo@codeaurora.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mmc@vger.kernel.org \
--cc=linux-wireless@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=pali@kernel.org \
--cc=robh+dt@kernel.org \
--cc=ulf.hansson@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).