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[media] pctv452e: don't do DMA on stack
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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.

Reviewed-by: Patrick Boettcher <patrick.boettcher@posteo.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Mauro Carvalho Chehab committed Oct 14, 2016
1 parent c3a66e9 commit 73d5c5c
Showing 1 changed file with 74 additions and 55 deletions.
129 changes: 74 additions & 55 deletions drivers/media/usb/dvb-usb/pctv452e.c
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Original file line number Diff line number Diff line change
Expand Up @@ -97,13 +97,14 @@ struct pctv452e_state {
u8 c; /* transaction counter, wraps around... */
u8 initialized; /* set to 1 if 0x15 has been sent */
u16 last_rc_key;

unsigned char data[80];
};

static int tt3650_ci_msg(struct dvb_usb_device *d, u8 cmd, u8 *data,
unsigned int write_len, unsigned int read_len)
{
struct pctv452e_state *state = (struct pctv452e_state *)d->priv;
u8 buf[64];
u8 id;
unsigned int rlen;
int ret;
Expand All @@ -112,33 +113,36 @@ static int tt3650_ci_msg(struct dvb_usb_device *d, u8 cmd, u8 *data,
BUG_ON(write_len > 64 - 4);
BUG_ON(read_len > 64 - 4);

mutex_lock(&state->ca_mutex);
id = state->c++;

buf[0] = SYNC_BYTE_OUT;
buf[1] = id;
buf[2] = cmd;
buf[3] = write_len;
state->data[0] = SYNC_BYTE_OUT;
state->data[1] = id;
state->data[2] = cmd;
state->data[3] = write_len;

memcpy(buf + 4, data, write_len);
memcpy(state->data + 4, data, write_len);

rlen = (read_len > 0) ? 64 : 0;
ret = dvb_usb_generic_rw(d, buf, 4 + write_len,
buf, rlen, /* delay_ms */ 0);
ret = dvb_usb_generic_rw(d, state->data, 4 + write_len,
state->data, rlen, /* delay_ms */ 0);
if (0 != ret)
goto failed;

ret = -EIO;
if (SYNC_BYTE_IN != buf[0] || id != buf[1])
if (SYNC_BYTE_IN != state->data[0] || id != state->data[1])
goto failed;

memcpy(data, buf + 4, read_len);
memcpy(data, state->data + 4, read_len);

mutex_unlock(&state->ca_mutex);
return 0;

failed:
err("CI error %d; %02X %02X %02X -> %*ph.",
ret, SYNC_BYTE_OUT, id, cmd, 3, buf);
ret, SYNC_BYTE_OUT, id, cmd, 3, state->data);

mutex_unlock(&state->ca_mutex);
return ret;
}

Expand Down Expand Up @@ -405,52 +409,53 @@ static int pctv452e_i2c_msg(struct dvb_usb_device *d, u8 addr,
u8 *rcv_buf, u8 rcv_len)
{
struct pctv452e_state *state = (struct pctv452e_state *)d->priv;
u8 buf[64];
u8 id;
int ret;

mutex_lock(&state->ca_mutex);
id = state->c++;

ret = -EINVAL;
if (snd_len > 64 - 7 || rcv_len > 64 - 7)
goto failed;

buf[0] = SYNC_BYTE_OUT;
buf[1] = id;
buf[2] = PCTV_CMD_I2C;
buf[3] = snd_len + 3;
buf[4] = addr << 1;
buf[5] = snd_len;
buf[6] = rcv_len;
state->data[0] = SYNC_BYTE_OUT;
state->data[1] = id;
state->data[2] = PCTV_CMD_I2C;
state->data[3] = snd_len + 3;
state->data[4] = addr << 1;
state->data[5] = snd_len;
state->data[6] = rcv_len;

memcpy(buf + 7, snd_buf, snd_len);
memcpy(state->data + 7, snd_buf, snd_len);

ret = dvb_usb_generic_rw(d, buf, 7 + snd_len,
buf, /* rcv_len */ 64,
ret = dvb_usb_generic_rw(d, state->data, 7 + snd_len,
state->data, /* rcv_len */ 64,
/* delay_ms */ 0);
if (ret < 0)
goto failed;

/* TT USB protocol error. */
ret = -EIO;
if (SYNC_BYTE_IN != buf[0] || id != buf[1])
if (SYNC_BYTE_IN != state->data[0] || id != state->data[1])
goto failed;

/* I2C device didn't respond as expected. */
ret = -EREMOTEIO;
if (buf[5] < snd_len || buf[6] < rcv_len)
if (state->data[5] < snd_len || state->data[6] < rcv_len)
goto failed;

memcpy(rcv_buf, buf + 7, rcv_len);
memcpy(rcv_buf, state->data + 7, rcv_len);
mutex_unlock(&state->ca_mutex);

return rcv_len;

failed:
err("I2C error %d; %02X %02X %02X %02X %02X -> "
"%02X %02X %02X %02X %02X.",
err("I2C error %d; %02X %02X %02X %02X %02X -> %*ph",
ret, SYNC_BYTE_OUT, id, addr << 1, snd_len, rcv_len,
buf[0], buf[1], buf[4], buf[5], buf[6]);
7, state->data);

mutex_unlock(&state->ca_mutex);
return ret;
}

Expand Down Expand Up @@ -499,8 +504,7 @@ static u32 pctv452e_i2c_func(struct i2c_adapter *adapter)
static int pctv452e_power_ctrl(struct dvb_usb_device *d, int i)
{
struct pctv452e_state *state = (struct pctv452e_state *)d->priv;
u8 b0[] = { 0xaa, 0, PCTV_CMD_RESET, 1, 0 };
u8 rx[PCTV_ANSWER_LEN];
u8 *rx;
int ret;

info("%s: %d\n", __func__, i);
Expand All @@ -511,72 +515,87 @@ static int pctv452e_power_ctrl(struct dvb_usb_device *d, int i)
if (state->initialized)
return 0;

rx = kmalloc(PCTV_ANSWER_LEN, GFP_KERNEL);
if (!rx)
return -ENOMEM;

mutex_lock(&state->ca_mutex);
/* hmm where shoud this should go? */
ret = usb_set_interface(d->udev, 0, ISOC_INTERFACE_ALTERNATIVE);
if (ret != 0)
info("%s: Warning set interface returned: %d\n",
__func__, ret);

/* this is a one-time initialization, dont know where to put */
b0[1] = state->c++;
state->data[0] = 0xaa;
state->data[1] = state->c++;
state->data[2] = PCTV_CMD_RESET;
state->data[3] = 1;
state->data[4] = 0;
/* reset board */
ret = dvb_usb_generic_rw(d, b0, sizeof(b0), rx, PCTV_ANSWER_LEN, 0);
ret = dvb_usb_generic_rw(d, state->data, 5, rx, PCTV_ANSWER_LEN, 0);
if (ret)
return ret;
goto ret;

b0[1] = state->c++;
b0[4] = 1;
state->data[1] = state->c++;
state->data[4] = 1;
/* reset board (again?) */
ret = dvb_usb_generic_rw(d, b0, sizeof(b0), rx, PCTV_ANSWER_LEN, 0);
ret = dvb_usb_generic_rw(d, state->data, 5, rx, PCTV_ANSWER_LEN, 0);
if (ret)
return ret;
goto ret;

state->initialized = 1;

return 0;
ret:
mutex_unlock(&state->ca_mutex);
kfree(rx);
return ret;
}

static int pctv452e_rc_query(struct dvb_usb_device *d)
{
struct pctv452e_state *state = (struct pctv452e_state *)d->priv;
u8 b[CMD_BUFFER_SIZE];
u8 rx[PCTV_ANSWER_LEN];
int ret, i;
u8 id = state->c++;
u8 id;

mutex_lock(&state->ca_mutex);
id = state->c++;

/* prepare command header */
b[0] = SYNC_BYTE_OUT;
b[1] = id;
b[2] = PCTV_CMD_IR;
b[3] = 0;
state->data[0] = SYNC_BYTE_OUT;
state->data[1] = id;
state->data[2] = PCTV_CMD_IR;
state->data[3] = 0;

/* send ir request */
ret = dvb_usb_generic_rw(d, b, 4, rx, PCTV_ANSWER_LEN, 0);
ret = dvb_usb_generic_rw(d, state->data, 4,
state->data, PCTV_ANSWER_LEN, 0);
if (ret != 0)
return ret;
goto ret;

if (debug > 3) {
info("%s: read: %2d: %*ph: ", __func__, ret, 3, rx);
for (i = 0; (i < rx[3]) && ((i+3) < PCTV_ANSWER_LEN); i++)
info(" %02x", rx[i+3]);
info("%s: read: %2d: %*ph: ", __func__, ret, 3, state->data);
for (i = 0; (i < state->data[3]) && ((i + 3) < PCTV_ANSWER_LEN); i++)
info(" %02x", state->data[i + 3]);

info("\n");
}

if ((rx[3] == 9) && (rx[12] & 0x01)) {
if ((state->data[3] == 9) && (state->data[12] & 0x01)) {
/* got a "press" event */
state->last_rc_key = RC_SCANCODE_RC5(rx[7], rx[6]);
state->last_rc_key = RC_SCANCODE_RC5(state->data[7], state->data[6]);
if (debug > 2)
info("%s: cmd=0x%02x sys=0x%02x\n",
__func__, rx[6], rx[7]);
__func__, state->data[6], state->data[7]);

rc_keydown(d->rc_dev, RC_TYPE_RC5, state->last_rc_key, 0);
} else if (state->last_rc_key) {
rc_keyup(d->rc_dev);
state->last_rc_key = 0;
}

return 0;
ret:
mutex_unlock(&state->ca_mutex);
return ret;
}

static int pctv452e_read_mac_address(struct dvb_usb_device *d, u8 mac[6])
Expand Down

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