From: Mauro Carvalho Chehab <mchehab@s-opensource.com>
To: Kosuke Tatsukawa <tatsu@ab.jp.nec.com>
Cc: Linux Media Mailing List <linux-media@vger.kernel.org>,
"Mauro Carvalho Chehab" <mchehab@osg.samsung.com>,
Mauro Carvalho Chehab <mchehab@infradead.org>,
Andy Lutomirski <luto@amacapital.net>,
"Johannes Stezenbach" <js@linuxtv.org>,
Jiri Kosina <jikos@kernel.org>,
"Patrick Boettcher" <patrick.boettcher@posteo.de>,
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>,
"jrg.otte@gmail.com" <jrg.otte@gmail.com>,
Hans Verkuil <hans.verkuil@cisco.com>,
Wolfram Sang <wsa-dev@sang-engineering.com>,
Kosuke Tatsukawa <tatsu@ab.jp.nec.com>
Subject: [PATCH v2 .1 28/31] cpia2_usb: don't use stack for DMA
Date: Tue, 11 Oct 2016 23:18:17 -0300 [thread overview]
Message-ID: <20161011231817.331f1244@vento.lan> (raw)
In-Reply-To: <17EC94B0A072C34B8DCF0D30AD16044A028EFC0B@BPXM09GP.gisp.nec.co.jp>
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@osg.samsung.com>
--
v2.1: As pointed by Kosuke Tatsukawa, I forgot to replace "registers" var
to "buf" at one of the usb_control_msg() calls.
diff --git a/drivers/media/usb/cpia2/cpia2_usb.c b/drivers/media/usb/cpia2/cpia2_usb.c
index 13620cdf0599..e9100a235831 100644
--- a/drivers/media/usb/cpia2/cpia2_usb.c
+++ b/drivers/media/usb/cpia2/cpia2_usb.c
@@ -545,18 +545,30 @@ static void free_sbufs(struct camera_data *cam)
static int write_packet(struct usb_device *udev,
u8 request, u8 * registers, u16 start, size_t size)
{
+ unsigned char *buf;
+ int ret;
+
if (!registers || size <= 0)
return -EINVAL;
- return usb_control_msg(udev,
+ buf = kmalloc(size, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ memcpy(buf, registers, size);
+
+ ret = usb_control_msg(udev,
usb_sndctrlpipe(udev, 0),
request,
USB_TYPE_VENDOR | USB_RECIP_DEVICE,
start, /* value */
0, /* index */
- registers, /* buffer */
+ buf, /* buffer */
size,
HZ);
+
+ kfree(buf);
+ return ret;
}
/****************************************************************************
@@ -567,18 +579,32 @@ static int write_packet(struct usb_device *udev,
static int read_packet(struct usb_device *udev,
u8 request, u8 * registers, u16 start, size_t size)
{
+ unsigned char *buf;
+ int ret;
+
if (!registers || size <= 0)
return -EINVAL;
- return usb_control_msg(udev,
+ buf = kmalloc(size, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ ret = usb_control_msg(udev,
usb_rcvctrlpipe(udev, 0),
request,
USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_DEVICE,
start, /* value */
0, /* index */
- registers, /* buffer */
+ buf, /* buffer */
size,
HZ);
+
+ if (ret >= 0)
+ memcpy(registers, buf, size);
+
+ kfree(buf);
+
+ return ret;
}
/******************************************************************************
next prev parent reply other threads:[~2016-10-12 2:18 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-11 10:09 [PATCH v2 00/31] Don't use stack for DMA transers on media usb drivers Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 01/31] af9005: don't do DMA on stack Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 02/31] cinergyT2-core: " Mauro Carvalho Chehab
2016-10-15 20:54 ` Johannes Stezenbach
2016-10-17 17:12 ` Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 03/31] cinergyT2-core: handle error code on RC query Mauro Carvalho Chehab
2016-10-12 2:13 ` [PATCH v2.1 " Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 04/31] cinergyT2-fe: cache stats at cinergyt2_fe_read_status() Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 05/31] cinergyT2-fe: don't do DMA on stack Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 06/31] cxusb: " Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 07/31] dib0700: be sure that dib0700_ctrl_rd() users can do DMA Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 08/31] dib0700_core: don't use stack on I2C reads Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 09/31] dibusb: don't do DMA on stack Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 10/31] dibusb: handle error code on RC query Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 11/31] digitv: don't do DMA on stack Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 12/31] dtt200u-fe: don't keep waiting for lock at set_frontend() Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 13/31] dtt200u-fe: don't do DMA on stack Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 14/31] dtt200u-fe: handle errors on USB control messages Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 15/31] dtt200u: don't do DMA on stack Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 16/31] dtt200u: handle USB control message errors Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 17/31] dtv5100: don't do DMA on stack Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 18/31] gp8psk: " Mauro Carvalho Chehab
2016-11-06 19:51 ` VDR User
2016-11-07 11:29 ` Johannes Stezenbach
2016-11-07 12:53 ` Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 19/31] gp8psk: don't go past the buffer size Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 20/31] nova-t-usb2: don't do DMA on stack Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 21/31] pctv452e: " Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 22/31] pctv452e: don't call BUG_ON() on non-fatal error Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 23/31] technisat-usb2: use DMA buffers for I2C transfers Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 24/31] dvb-usb: warn if return value for USB read/write routines is not checked Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 25/31] nova-t-usb2: handle error code on RC query Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 26/31] dw2102: return error if su3000_power_ctrl() fails Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 27/31] digitv: handle error code on RC query Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 28/31] cpia2_usb: don't use stack for DMA Mauro Carvalho Chehab
2016-10-11 22:56 ` Kosuke Tatsukawa
2016-10-12 2:18 ` Mauro Carvalho Chehab [this message]
2016-10-12 2:19 ` Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 29/31] s2255drv: " Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 30/31] stk-webcam: " Mauro Carvalho Chehab
2016-10-11 10:09 ` [PATCH v2 31/31] flexcop-usb: " Mauro Carvalho Chehab
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