From: Patrick Boettcher <patrick.boettcher@posteo.de>
To: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Cc: "Linux Media Mailing List" <linux-media@vger.kernel.org>,
"Mauro Carvalho Chehab" <mchehab@infradead.org>,
"Andy Lutomirski" <luto@amacapital.net>,
"Johannes Stezenbach" <js@linuxtv.org>,
"Jiri Kosina" <jikos@kernel.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
"Andy Lutomirski" <luto@kernel.org>,
"Michael Krufky" <mkrufky@linuxtv.org>,
"Mauro Carvalho Chehab" <mchehab@kernel.org>,
"Jörg Otte" <jrg.otte@gmail.com>
Subject: Re: [PATCH 11/26] digitv: don't do DMA on stack
Date: Mon, 10 Oct 2016 08:36:56 +0200 [thread overview]
Message-ID: <20161010083656.4fa6610e@posteo.de> (raw)
In-Reply-To: <0ab236ba1bfe2935b2cda329b706fcc1ef55edeb.1475860773.git.mchehab@s-opensource.com>
On Fri, 7 Oct 2016 14:24:21 -0300
Mauro Carvalho Chehab <mchehab@s-opensource.com> wrote:
> The USB control messages require DMA to work. We cannot pass
> a stack-allocated buffer, as it is not warranted that the
> stack would be into a DMA enabled area.
>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
> ---
> drivers/media/usb/dvb-usb/digitv.c | 20 +++++++++++---------
> drivers/media/usb/dvb-usb/digitv.h | 3 +++
> 2 files changed, 14 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/media/usb/dvb-usb/digitv.c
> b/drivers/media/usb/dvb-usb/digitv.c index 63134335c994..09f8c28bd4db
> 100644 --- a/drivers/media/usb/dvb-usb/digitv.c
> +++ b/drivers/media/usb/dvb-usb/digitv.c
> @@ -28,20 +28,22 @@ DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);
> static int digitv_ctrl_msg(struct dvb_usb_device *d,
> u8 cmd, u8 vv, u8 *wbuf, int wlen, u8 *rbuf, int
> rlen) {
> + struct digitv_state *st = d->priv;
> int wo = (rbuf == NULL || rlen == 0); /* write-only */
> - u8 sndbuf[7],rcvbuf[7];
> - memset(sndbuf,0,7); memset(rcvbuf,0,7);
>
> - sndbuf[0] = cmd;
> - sndbuf[1] = vv;
> - sndbuf[2] = wo ? wlen : rlen;
> + memset(st->sndbuf, 0, 7);
> + memset(st->rcvbuf, 0, 7);
> +
> + st->sndbuf[0] = cmd;
> + st->sndbuf[1] = vv;
> + st->sndbuf[2] = wo ? wlen : rlen;
>
> if (wo) {
> - memcpy(&sndbuf[3],wbuf,wlen);
> - dvb_usb_generic_write(d,sndbuf,7);
> + memcpy(&st->sndbuf[3], wbuf, wlen);
> + dvb_usb_generic_write(d, st->sndbuf, 7);
> } else {
> - dvb_usb_generic_rw(d,sndbuf,7,rcvbuf,7,10);
> - memcpy(rbuf,&rcvbuf[3],rlen);
> + dvb_usb_generic_rw(d, st->sndbuf, 7, st->rcvbuf, 7,
> 10);
> + memcpy(rbuf, &st->rcvbuf[3], rlen);
> }
> return 0;
> }
> diff --git a/drivers/media/usb/dvb-usb/digitv.h
> b/drivers/media/usb/dvb-usb/digitv.h index 908c09f4966b..cf104689bdff
> 100644 --- a/drivers/media/usb/dvb-usb/digitv.h
> +++ b/drivers/media/usb/dvb-usb/digitv.h
> @@ -6,6 +6,9 @@
>
> struct digitv_state {
> int is_nxt6000;
> +
> + unsigned char sndbuf[7];
> + unsigned char rcvbuf[7];
> };
>
> /* protocol (from usblogging and the SDK:
Reviewed-By: Patrick Boettcher <patrick.boettcher@posteo.de>
next prev parent reply other threads:[~2016-10-10 6:36 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-07 17:24 [PATCH 00/26] Don't use stack for DMA transers on dvb-usb drivers Mauro Carvalho Chehab
2016-10-07 17:24 ` [PATCH 01/26] af9005: don't do DMA on stack Mauro Carvalho Chehab
2016-10-07 17:24 ` [PATCH 02/26] cinergyT2-core: " Mauro Carvalho Chehab
2016-10-10 6:39 ` Patrick Boettcher
2016-10-07 17:24 ` [PATCH 03/26] cinergyT2-core:: handle error code on RC query Mauro Carvalho Chehab
2016-10-07 17:24 ` [PATCH 04/26] cinergyT2-fe: cache stats at cinergyt2_fe_read_status() Mauro Carvalho Chehab
2016-10-07 17:24 ` [PATCH 05/26] cinergyT2-fe: don't do DMA on stack Mauro Carvalho Chehab
2016-10-10 6:39 ` Patrick Boettcher
2016-10-07 17:24 ` [PATCH 06/26] cxusb: " Mauro Carvalho Chehab
2016-10-10 6:38 ` Patrick Boettcher
2016-10-07 17:24 ` [PATCH 07/26] dib0700: be sure that dib0700_ctrl_rd() users can do DMA Mauro Carvalho Chehab
2016-10-10 6:38 ` Patrick Boettcher
2016-10-07 17:24 ` [PATCH 08/26] dib0700_core: don't use stack on I2C reads Mauro Carvalho Chehab
2016-10-10 6:37 ` Patrick Boettcher
2016-10-07 17:24 ` [PATCH 09/26] dibusb: don't do DMA on stack Mauro Carvalho Chehab
2016-10-10 6:37 ` Patrick Boettcher
2016-10-07 17:24 ` [PATCH 10/26] dibusb: handle error code on RC query Mauro Carvalho Chehab
2016-10-07 17:24 ` [PATCH 11/26] digitv: don't do DMA on stack Mauro Carvalho Chehab
2016-10-10 6:36 ` Patrick Boettcher [this message]
2016-10-07 17:24 ` [PATCH 12/26] dtt200u-fe: " Mauro Carvalho Chehab
2016-10-07 17:24 ` [PATCH 13/26] dtt200u-fe: handle errors on USB control messages Mauro Carvalho Chehab
2016-10-07 17:24 ` [PATCH 14/26] dtt200u: don't do DMA on stack Mauro Carvalho Chehab
2016-10-10 6:36 ` Patrick Boettcher
2016-10-07 17:24 ` [PATCH 15/26] dtt200u: handle USB control message errors Mauro Carvalho Chehab
2016-10-07 17:24 ` [PATCH 16/26] dtv5100: : don't do DMA on stack Mauro Carvalho Chehab
2016-10-07 17:24 ` [PATCH 17/26] gp8psk: " Mauro Carvalho Chehab
2016-10-07 17:24 ` [PATCH 18/26] gp8psk: don't go past the buffer size Mauro Carvalho Chehab
2016-10-07 17:24 ` [PATCH 19/26] nova-t-usb2: don't do DMA on stack Mauro Carvalho Chehab
2016-10-10 6:35 ` Patrick Boettcher
2016-10-07 17:24 ` [PATCH 20/26] pctv452e: " Mauro Carvalho Chehab
2016-10-10 6:35 ` Patrick Boettcher
2016-10-07 17:24 ` [PATCH 21/26] pctv452e: don't call BUG_ON() on non-fatal error Mauro Carvalho Chehab
2016-10-08 10:11 ` [PATCH v2 " Mauro Carvalho Chehab
2016-10-07 17:24 ` [PATCH 22/26] technisat-usb2: use DMA buffers for I2C transfers Mauro Carvalho Chehab
2016-10-10 6:34 ` Patrick Boettcher
2016-10-07 17:24 ` [PATCH 23/26] dvb-usb: warn if return value for USB read/write routines is not checked Mauro Carvalho Chehab
2016-10-07 17:24 ` [PATCH 24/26] nova-t-usb2: handle error code on RC query Mauro Carvalho Chehab
2016-10-07 17:24 ` [PATCH 25/26] dw2102: return error if su3000_power_ctrl() fails Mauro Carvalho Chehab
2016-10-07 17:24 ` [PATCH 26/26] digitv: handle error code on RC query Mauro Carvalho Chehab
2016-10-10 11:24 ` [PATCH 00/26] Don't use stack for DMA transers on dvb-usb drivers Antti Palosaari
2016-10-10 11:44 ` Michael Ira Krufky
2016-10-11 10:12 ` Mauro Carvalho Chehab
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=20161010083656.4fa6610e@posteo.de \
--to=patrick.boettcher@posteo.de \
--cc=jikos@kernel.org \
--cc=jrg.otte@gmail.com \
--cc=js@linuxtv.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=luto@kernel.org \
--cc=mchehab@infradead.org \
--cc=mchehab@kernel.org \
--cc=mchehab@s-opensource.com \
--cc=mkrufky@linuxtv.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).