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Groups > linux.kernel > #1498712
| From | Mauro Carvalho Chehab <mchehab@s-opensource.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v2 28/31] cpia2_usb: don't use stack for DMA |
| Date | 2016-10-11 12:20 +0200 |
| Message-ID | <sr2ka-5sy-23@gated-at.bofh.it> (permalink) |
| References | <sr2k9-5sy-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
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>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
---
drivers/media/usb/cpia2/cpia2_usb.c | 32 +++++++++++++++++++++++++++++---
1 file changed, 29 insertions(+), 3 deletions(-)
diff --git a/drivers/media/usb/cpia2/cpia2_usb.c b/drivers/media/usb/cpia2/cpia2_usb.c
index 13620cdf0599..417d683b237d 100644
--- a/drivers/media/usb/cpia2/cpia2_usb.c
+++ b/drivers/media/usb/cpia2/cpia2_usb.c
@@ -545,10 +545,19 @@ 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,
@@ -557,6 +566,9 @@ static int write_packet(struct usb_device *udev,
registers, /* 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;
}
/******************************************************************************
--
2.7.4
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH v2 00/31] Don't use stack for DMA transers on media usb drivers Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 04/31] cinergyT2-fe: cache stats at cinergyt2_fe_read_status() Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 05/31] cinergyT2-fe: don't do DMA on stack Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 29/31] s2255drv: don't use stack for DMA Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 26/31] dw2102: return error if su3000_power_ctrl() fails Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 30/31] stk-webcam: don't use stack for DMA Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 28/31] cpia2_usb: don't use stack for DMA Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
Re: [PATCH v2 28/31] cpia2_usb: don't use stack for DMA Kosuke Tatsukawa <tatsu@ab.jp.nec.com> - 2016-10-12 01:00 +0200
[PATCH v2 .1 28/31] cpia2_usb: don't use stack for DMA Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-12 04:20 +0200
Re: [PATCH v2 28/31] cpia2_usb: don't use stack for DMA Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-12 04:20 +0200
[PATCH v2 01/31] af9005: don't do DMA on stack Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 15/31] dtt200u: don't do DMA on stack Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 24/31] dvb-usb: warn if return value for USB read/write routines is not checked Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 02/31] cinergyT2-core: don't do DMA on stack Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 07/31] dib0700: be sure that dib0700_ctrl_rd() users can do DMA Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 11/31] digitv: don't do DMA on stack Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 17/31] dtv5100: don't do DMA on stack Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 25/31] nova-t-usb2: handle error code on RC query Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 18/31] gp8psk: don't do DMA on stack Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 20/31] nova-t-usb2: don't do DMA on stack Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 31/31] flexcop-usb: don't use stack for DMA Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 22/31] pctv452e: don't call BUG_ON() on non-fatal error Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 10/31] dibusb: handle error code on RC query Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 27/31] digitv: handle error code on RC query Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 16/31] dtt200u: handle USB control message errors Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 13/31] dtt200u-fe: don't do DMA on stack Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 21/31] pctv452e: don't do DMA on stack Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 19/31] gp8psk: don't go past the buffer size Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 12/31] dtt200u-fe: don't keep waiting for lock at set_frontend() Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 08/31] dib0700_core: don't use stack on I2C reads Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
[PATCH v2 06/31] cxusb: don't do DMA on stack Mauro Carvalho Chehab <mchehab@s-opensource.com> - 2016-10-11 12:20 +0200
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