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Subject[PATCH v2 31/31] flexcop-usb: don't use stack for DMA
Date
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.

While here, remove a dead function calling usb_control_msg().

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
---
drivers/media/usb/b2c2/flexcop-usb.c | 105 +++++++++++++++++++++++------------
drivers/media/usb/b2c2/flexcop-usb.h | 4 ++
2 files changed, 72 insertions(+), 37 deletions(-)

diff --git a/drivers/media/usb/b2c2/flexcop-usb.c b/drivers/media/usb/b2c2/flexcop-usb.c
index d4bdba60b0f7..f26fc530564b 100644
--- a/drivers/media/usb/b2c2/flexcop-usb.c
+++ b/drivers/media/usb/b2c2/flexcop-usb.c
@@ -73,23 +73,34 @@ static int flexcop_usb_readwrite_dw(struct flexcop_device *fc, u16 wRegOffsPCI,
u8 request_type = (read ? USB_DIR_IN : USB_DIR_OUT) | USB_TYPE_VENDOR;
u8 wAddress = B2C2_FLEX_PCIOFFSET_TO_INTERNALADDR(wRegOffsPCI) |
(read ? 0x80 : 0);
+ int ret;

- int len = usb_control_msg(fc_usb->udev,
+ mutex_lock(&fc_usb->data_mutex);
+ if (!read)
+ memcpy(fc_usb->data, val, sizeof(*val));
+
+ ret = usb_control_msg(fc_usb->udev,
read ? B2C2_USB_CTRL_PIPE_IN : B2C2_USB_CTRL_PIPE_OUT,
request,
request_type, /* 0xc0 read or 0x40 write */
wAddress,
0,
- val,
+ fc_usb->data,
sizeof(u32),
B2C2_WAIT_FOR_OPERATION_RDW * HZ);

- if (len != sizeof(u32)) {
+ if (ret != sizeof(u32)) {
err("error while %s dword from %d (%d).", read ? "reading" :
"writing", wAddress, wRegOffsPCI);
- return -EIO;
+ if (ret >= 0)
+ ret = -EIO;
}
- return 0;
+
+ if (read && ret >= 0)
+ memcpy(val, fc_usb->data, sizeof(*val));
+ mutex_unlock(&fc_usb->data_mutex);
+
+ return ret;
}
/*
* DKT 010817 - add support for V8 memory read/write and flash update
@@ -100,9 +111,14 @@ static int flexcop_usb_v8_memory_req(struct flexcop_usb *fc_usb,
{
u8 request_type = USB_TYPE_VENDOR;
u16 wIndex;
- int nWaitTime, pipe, len;
+ int nWaitTime, pipe, ret;
wIndex = page << 8;

+ if (buflen > sizeof(fc_usb->data)) {
+ err("Buffer size bigger than max URB control message\n");
+ return -EIO;
+ }
+
switch (req) {
case B2C2_USB_READ_V8_MEM:
nWaitTime = B2C2_WAIT_FOR_OPERATION_V8READ;
@@ -127,17 +143,32 @@ static int flexcop_usb_v8_memory_req(struct flexcop_usb *fc_usb,
deb_v8("v8mem: %02x %02x %04x %04x, len: %d\n", request_type, req,
wAddress, wIndex, buflen);

- len = usb_control_msg(fc_usb->udev, pipe,
+ mutex_lock(&fc_usb->data_mutex);
+
+ if ((request_type & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT)
+ memcpy(fc_usb->data, pbBuffer, buflen);
+
+ ret = usb_control_msg(fc_usb->udev, pipe,
req,
request_type,
wAddress,
wIndex,
- pbBuffer,
+ fc_usb->data,
buflen,
nWaitTime * HZ);
+ if (ret != buflen)
+ ret = -EIO;

- debug_dump(pbBuffer, len, deb_v8);
- return len == buflen ? 0 : -EIO;
+ if (ret >= 0) {
+ ret = 0;
+ if ((request_type & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN)
+ memcpy(pbBuffer, fc_usb->data, buflen);
+ }
+
+ mutex_unlock(&fc_usb->data_mutex);
+
+ debug_dump(pbBuffer, ret, deb_v8);
+ return ret;
}

#define bytes_left_to_read_on_page(paddr,buflen) \
@@ -196,29 +227,6 @@ static int flexcop_usb_get_mac_addr(struct flexcop_device *fc, int extended)
fc->dvb_adapter.proposed_mac, 6);
}

-#if 0
-static int flexcop_usb_utility_req(struct flexcop_usb *fc_usb, int set,
- flexcop_usb_utility_function_t func, u8 extra, u16 wIndex,
- u16 buflen, u8 *pvBuffer)
-{
- u16 wValue;
- u8 request_type = (set ? USB_DIR_OUT : USB_DIR_IN) | USB_TYPE_VENDOR;
- int nWaitTime = 2,
- pipe = set ? B2C2_USB_CTRL_PIPE_OUT : B2C2_USB_CTRL_PIPE_IN, len;
- wValue = (func << 8) | extra;
-
- len = usb_control_msg(fc_usb->udev,pipe,
- B2C2_USB_UTILITY,
- request_type,
- wValue,
- wIndex,
- pvBuffer,
- buflen,
- nWaitTime * HZ);
- return len == buflen ? 0 : -EIO;
-}
-#endif
-
/* usb i2c stuff */
static int flexcop_usb_i2c_req(struct flexcop_i2c_adapter *i2c,
flexcop_usb_request_t req, flexcop_usb_i2c_function_t func,
@@ -226,9 +234,14 @@ static int flexcop_usb_i2c_req(struct flexcop_i2c_adapter *i2c,
{
struct flexcop_usb *fc_usb = i2c->fc->bus_specific;
u16 wValue, wIndex;
- int nWaitTime,pipe,len;
+ int nWaitTime, pipe, ret;
u8 request_type = USB_TYPE_VENDOR;

+ if (buflen > sizeof(fc_usb->data)) {
+ err("Buffer size bigger than max URB control message\n");
+ return -EIO;
+ }
+
switch (func) {
case USB_FUNC_I2C_WRITE:
case USB_FUNC_I2C_MULTIWRITE:
@@ -257,15 +270,32 @@ static int flexcop_usb_i2c_req(struct flexcop_i2c_adapter *i2c,
wValue & 0xff, wValue >> 8,
wIndex & 0xff, wIndex >> 8);

- len = usb_control_msg(fc_usb->udev,pipe,
+ mutex_lock(&fc_usb->data_mutex);
+
+ if ((request_type & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT)
+ memcpy(fc_usb->data, buf, buflen);
+
+ ret = usb_control_msg(fc_usb->udev,pipe,
req,
request_type,
wValue,
wIndex,
- buf,
+ fc_usb->data,
buflen,
nWaitTime * HZ);
- return len == buflen ? 0 : -EREMOTEIO;
+
+ if (ret != buflen)
+ ret = -EIO;
+
+ if (ret >= 0) {
+ ret = 0;
+ if ((request_type & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN)
+ memcpy(buf, fc_usb->data, buflen);
+ }
+
+ mutex_unlock(&fc_usb->data_mutex);
+
+ return 0;
}

/* actual bus specific access functions,
@@ -516,6 +546,7 @@ static int flexcop_usb_probe(struct usb_interface *intf,
/* general flexcop init */
fc_usb = fc->bus_specific;
fc_usb->fc_dev = fc;
+ mutex_init(&fc_usb->data_mutex);

fc->read_ibi_reg = flexcop_usb_read_ibi_reg;
fc->write_ibi_reg = flexcop_usb_write_ibi_reg;
diff --git a/drivers/media/usb/b2c2/flexcop-usb.h b/drivers/media/usb/b2c2/flexcop-usb.h
index 92529a9c4475..25ad43166e78 100644
--- a/drivers/media/usb/b2c2/flexcop-usb.h
+++ b/drivers/media/usb/b2c2/flexcop-usb.h
@@ -29,6 +29,10 @@ struct flexcop_usb {

u8 tmp_buffer[1023+190];
int tmp_buffer_length;
+
+ /* for URB control messages */
+ u8 data[80];
+ struct mutex data_mutex;
};

#if 0
--
2.7.4

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