[media] DiB0700: get rid of on-stack dma buffers

This patch removes the on-stack buffers for USB DMA transfers.

This is an alternative version of the patch discussed by Florian here:
http://thread.gmane.org/gmane.linux.kernel/1115695/

Signed-off-by: Olivier Grenie <olivier.grenie@dibcom.fr>
Signed-off-by: Patrick Boettcher <patrick.boettcher@dibcom.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

2 files changed, 136 insertions, 87 deletions

diff --git a/drivers/media/dvb/dvb-usb/dib0700.h b/drivers/media/dvb/dvb-usb/dib0700.h
index b2a87f2c2c3e..9bd6d51b3b93 100644
--- a/drivers/media/dvb/dvb-usb/dib0700.h
+++ b/drivers/media/dvb/dvb-usb/dib0700.h
@@ -46,8 +46,9 @@ struct dib0700_state {
         u8 is_dib7000pc;
         u8 fw_use_new_i2c_api;
         u8 disable_streaming_master_mode;
-    u32 fw_version;
-    u32 nb_packet_buffer_size;
+        u32 fw_version;
+        u32 nb_packet_buffer_size;
+        u8 buf[255];
 };
 
 extern int dib0700_get_version(struct dvb_usb_device *d, u32 *hwversion,
diff --git a/drivers/media/dvb/dvb-usb/dib0700_core.c b/drivers/media/dvb/dvb-usb/dib0700_core.c
index b79af68c54ae..0325825961b9 100644
--- a/drivers/media/dvb/dvb-usb/dib0700_core.c
+++ b/drivers/media/dvb/dvb-usb/dib0700_core.c
@@ -27,19 +27,25 @@ DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);
 int dib0700_get_version(struct dvb_usb_device *d, u32 *hwversion,
                         u32 *romversion, u32 *ramversion, u32 *fwtype)
 {
-        u8 b[16];
-        int ret = usb_control_msg(d->udev, usb_rcvctrlpipe(d->udev, 0),
+        struct dib0700_state *st = d->priv;
+        int ret;
+
+        ret = usb_control_msg(d->udev, usb_rcvctrlpipe(d->udev, 0),
                                   REQUEST_GET_VERSION,
                                   USB_TYPE_VENDOR | USB_DIR_IN, 0, 0,
-                                  b, sizeof(b), USB_CTRL_GET_TIMEOUT);
+                                  st->buf, 16, USB_CTRL_GET_TIMEOUT);
         if (hwversion != NULL)
-                *hwversion  = (b[0] << 24)  | (b[1] << 16)  | (b[2] << 8)  | b[3];
+                *hwversion  = (st->buf[0] << 24)  | (st->buf[1] << 16)  |
+                        (st->buf[2] << 8)  | st->buf[3];
         if (romversion != NULL)
-                *romversion = (b[4] << 24)  | (b[5] << 16)  | (b[6] << 8)  | b[7];
+                *romversion = (st->buf[4] << 24)  | (st->buf[5] << 16)  |
+                        (st->buf[6] << 8)  | st->buf[7];
         if (ramversion != NULL)
-                *ramversion = (b[8] << 24)  | (b[9] << 16)  | (b[10] << 8) | b[11];
+                *ramversion = (st->buf[8] << 24)  | (st->buf[9] << 16)  |
+                        (st->buf[10] << 8) | st->buf[11];
         if (fwtype != NULL)
-                *fwtype     = (b[12] << 24) | (b[13] << 16) | (b[14] << 8) | b[15];
+                *fwtype     = (st->buf[12] << 24) | (st->buf[13] << 16) |
+                        (st->buf[14] << 8) | st->buf[15];
         return ret;
 }
 
@@ -101,24 +107,31 @@ int dib0700_ctrl_rd(struct dvb_usb_device *d, u8 *tx, u8 txlen, u8 *rx, u8 rxlen
 
 int dib0700_set_gpio(struct dvb_usb_device *d, enum dib07x0_gpios gpio, u8 gpio_dir, u8 gpio_val)
 {
-        u8 buf[3] = { REQUEST_SET_GPIO, gpio, ((gpio_dir & 0x01) << 7) | ((gpio_val & 0x01) << 6) };
-        return dib0700_ctrl_wr(d, buf, sizeof(buf));
+        struct dib0700_state *st = d->priv;
+        s16 ret;
+
+        st->buf[0] = REQUEST_SET_GPIO;
+        st->buf[1] = gpio;
+        st->buf[2] = ((gpio_dir & 0x01) << 7) | ((gpio_val & 0x01) << 6);
+
+        ret = dib0700_ctrl_wr(d, st->buf, 3);
+
+        return ret;
 }
 
 static int dib0700_set_usb_xfer_len(struct dvb_usb_device *d, u16 nb_ts_packets)
 {
         struct dib0700_state *st = d->priv;
-        u8 b[3];
         int ret;
 
         if (st->fw_version >= 0x10201) {
-                b[0] = REQUEST_SET_USB_XFER_LEN;
-                b[1] = (nb_ts_packets >> 8) & 0xff;
-                b[2] = nb_ts_packets & 0xff;
+                st->buf[0] = REQUEST_SET_USB_XFER_LEN;
+                st->buf[1] = (nb_ts_packets >> 8) & 0xff;
+                st->buf[2] = nb_ts_packets & 0xff;
 
                 deb_info("set the USB xfer len to %i Ts packet\n", nb_ts_packets);
 
-                ret = dib0700_ctrl_wr(d, b, sizeof(b));
+                ret = dib0700_ctrl_wr(d, st->buf, 3);
         } else {
                 deb_info("this firmware does not allow to change the USB xfer len\n");
                 ret = -EIO;
@@ -137,11 +150,11 @@ static int dib0700_i2c_xfer_new(struct i2c_adapter *adap, struct i2c_msg *msg,
            properly support i2c read calls not preceded by a write */
 
         struct dvb_usb_device *d = i2c_get_adapdata(adap);
+        struct dib0700_state *st = d->priv;
         uint8_t bus_mode = 1;  /* 0=eeprom bus, 1=frontend bus */
         uint8_t gen_mode = 0; /* 0=master i2c, 1=gpio i2c */
         uint8_t en_start = 0;
         uint8_t en_stop = 0;
-        uint8_t buf[255]; /* TBV: malloc ? */
         int result, i;
 
         /* Ensure nobody else hits the i2c bus while we're sending our
@@ -195,24 +208,24 @@ static int dib0700_i2c_xfer_new(struct i2c_adapter *adap, struct i2c_msg *msg,
 
                 } else {
                         /* Write request */
-                        buf[0] = REQUEST_NEW_I2C_WRITE;
-                        buf[1] = msg[i].addr << 1;
-                        buf[2] = (en_start << 7) | (en_stop << 6) |
+                        st->buf[0] = REQUEST_NEW_I2C_WRITE;
+                        st->buf[1] = msg[i].addr << 1;
+                        st->buf[2] = (en_start << 7) | (en_stop << 6) |
                                 (msg[i].len & 0x3F);
                         /* I2C ctrl + FE bus; */
-                        buf[3] = ((gen_mode << 6) & 0xC0) |
+                        st->buf[3] = ((gen_mode << 6) & 0xC0) |
                                  ((bus_mode << 4) & 0x30);
                         /* The Actual i2c payload */
-                        memcpy(&buf[4], msg[i].buf, msg[i].len);
+                        memcpy(&st->buf[4], msg[i].buf, msg[i].len);
 
                         deb_data(">>> ");
-                        debug_dump(buf, msg[i].len + 4, deb_data);
+                        debug_dump(st->buf, msg[i].len + 4, deb_data);
 
                         result = usb_control_msg(d->udev,
                                                  usb_sndctrlpipe(d->udev, 0),
                                                  REQUEST_NEW_I2C_WRITE,
                                                  USB_TYPE_VENDOR | USB_DIR_OUT,
-                                                 0, 0, buf, msg[i].len + 4,
+                                                 0, 0, st->buf, msg[i].len + 4,
                                                  USB_CTRL_GET_TIMEOUT);
                         if (result < 0) {
                                 deb_info("i2c write error (status = %d)\n", result);
@@ -231,27 +244,29 @@ static int dib0700_i2c_xfer_legacy(struct i2c_adapter *adap,
                                    struct i2c_msg *msg, int num)
 {
         struct dvb_usb_device *d = i2c_get_adapdata(adap);
+        struct dib0700_state *st = d->priv;
         int i,len;
-        u8 buf[255];
 
         if (mutex_lock_interruptible(&d->i2c_mutex) < 0)
                 return -EAGAIN;
 
         for (i = 0; i < num; i++) {
                 /* fill in the address */
-                buf[1] = msg[i].addr << 1;
+                st->buf[1] = msg[i].addr << 1;
                 /* fill the buffer */
-                memcpy(&buf[2], msg[i].buf, msg[i].len);
+                memcpy(&st->buf[2], msg[i].buf, msg[i].len);
 
                 /* write/read request */
                 if (i+1 < num && (msg[i+1].flags & I2C_M_RD)) {
-                        buf[0] = REQUEST_I2C_READ;
-                        buf[1] |= 1;
+                        st->buf[0] = REQUEST_I2C_READ;
+                        st->buf[1] |= 1;
 
                         /* special thing in the current firmware: when length is zero the read-failed */
-                        if ((len = dib0700_ctrl_rd(d, buf, msg[i].len + 2, msg[i+1].buf, msg[i+1].len)) <= 0) {
+                        len = dib0700_ctrl_rd(d, st->buf, msg[i].len + 2,
+                                        msg[i+1].buf, msg[i+1].len);
+                        if (len <= 0) {
                                 deb_info("I2C read failed on address 0x%02x\n",
-                                         msg[i].addr);
+                                                msg[i].addr);
                                 break;
                         }
 
@@ -259,13 +274,13 @@ static int dib0700_i2c_xfer_legacy(struct i2c_adapter *adap,
 
                         i++;
                 } else {
-                        buf[0] = REQUEST_I2C_WRITE;
-                        if (dib0700_ctrl_wr(d, buf, msg[i].len + 2) < 0)
+                        st->buf[0] = REQUEST_I2C_WRITE;
+                        if (dib0700_ctrl_wr(d, st->buf, msg[i].len + 2) < 0)
                                 break;
                 }
         }
-
         mutex_unlock(&d->i2c_mutex);
+
         return i;
 }
 
@@ -297,15 +312,23 @@ struct i2c_algorithm dib0700_i2c_algo = {
 int dib0700_identify_state(struct usb_device *udev, struct dvb_usb_device_properties *props,
                         struct dvb_usb_device_description **desc, int *cold)
 {
-        u8 b[16];
-        s16 ret = usb_control_msg(udev, usb_rcvctrlpipe(udev,0),
+        s16 ret;
+        u8 *b;
+
+        b = kmalloc(16, GFP_KERNEL);
+        if (!b)
+                return  -ENOMEM;
+
+
+        ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
                 REQUEST_GET_VERSION, USB_TYPE_VENDOR | USB_DIR_IN, 0, 0, b, 16, USB_CTRL_GET_TIMEOUT);
 
         deb_info("FW GET_VERSION length: %d\n",ret);
 
         *cold = ret <= 0;
-
         deb_info("cold: %d\n", *cold);
+
+        kfree(b);
         return 0;
 }
 
@@ -313,43 +336,50 @@ static int dib0700_set_clock(struct dvb_usb_device *d, u8 en_pll,
         u8 pll_src, u8 pll_range, u8 clock_gpio3, u16 pll_prediv,
         u16 pll_loopdiv, u16 free_div, u16 dsuScaler)
 {
-        u8 b[10];
-        b[0] = REQUEST_SET_CLOCK;
-        b[1] = (en_pll << 7) | (pll_src << 6) | (pll_range << 5) | (clock_gpio3 << 4);
-        b[2] = (pll_prediv >> 8)  & 0xff; // MSB
-        b[3] =  pll_prediv        & 0xff; // LSB
-        b[4] = (pll_loopdiv >> 8) & 0xff; // MSB
-        b[5] =  pll_loopdiv       & 0xff; // LSB
-        b[6] = (free_div >> 8)    & 0xff; // MSB
-        b[7] =  free_div          & 0xff; // LSB
-        b[8] = (dsuScaler >> 8)   & 0xff; // MSB
-        b[9] =  dsuScaler         & 0xff; // LSB
-
-        return dib0700_ctrl_wr(d, b, 10);
+        struct dib0700_state *st = d->priv;
+        s16 ret;
+
+        st->buf[0] = REQUEST_SET_CLOCK;
+        st->buf[1] = (en_pll << 7) | (pll_src << 6) |
+                (pll_range << 5) | (clock_gpio3 << 4);
+        st->buf[2] = (pll_prediv >> 8)  & 0xff; /* MSB */
+        st->buf[3] =  pll_prediv        & 0xff; /* LSB */
+        st->buf[4] = (pll_loopdiv >> 8) & 0xff; /* MSB */
+        st->buf[5] =  pll_loopdiv       & 0xff; /* LSB */
+        st->buf[6] = (free_div >> 8)    & 0xff; /* MSB */
+        st->buf[7] =  free_div          & 0xff; /* LSB */
+        st->buf[8] = (dsuScaler >> 8)   & 0xff; /* MSB */
+        st->buf[9] =  dsuScaler         & 0xff; /* LSB */
+
+        ret = dib0700_ctrl_wr(d, st->buf, 10);
+
+        return ret;
 }
 
 int dib0700_set_i2c_speed(struct dvb_usb_device *d, u16 scl_kHz)
 {
+        struct dib0700_state *st = d->priv;
         u16 divider;
-        u8 b[8];
 
         if (scl_kHz == 0)
                 return -EINVAL;
 
-        b[0] = REQUEST_SET_I2C_PARAM;
+        st->buf[0] = REQUEST_SET_I2C_PARAM;
         divider = (u16) (30000 / scl_kHz);
-        b[2] = (u8) (divider >> 8);
-        b[3] = (u8) (divider & 0xff);
+        st->buf[1] = 0;
+        st->buf[2] = (u8) (divider >> 8);
+        st->buf[3] = (u8) (divider & 0xff);
         divider = (u16) (72000 / scl_kHz);
-        b[4] = (u8) (divider >> 8);
-        b[5] = (u8) (divider & 0xff);
+        st->buf[4] = (u8) (divider >> 8);
+        st->buf[5] = (u8) (divider & 0xff);
         divider = (u16) (72000 / scl_kHz); /* clock: 72MHz */
-        b[6] = (u8) (divider >> 8);
-        b[7] = (u8) (divider & 0xff);
+        st->buf[6] = (u8) (divider >> 8);
+        st->buf[7] = (u8) (divider & 0xff);
 
         deb_info("setting I2C speed: %04x %04x %04x (%d kHz).",
-                (b[2] << 8) | (b[3]), (b[4] << 8) | b[5], (b[6] << 8) | b[7], scl_kHz);
-        return dib0700_ctrl_wr(d, b, 8);
+                (st->buf[2] << 8) | (st->buf[3]), (st->buf[4] << 8) |
+                st->buf[5], (st->buf[6] << 8) | st->buf[7], scl_kHz);
+        return dib0700_ctrl_wr(d, st->buf, 8);
 }
 
 
@@ -364,32 +394,45 @@ int dib0700_ctrl_clock(struct dvb_usb_device *d, u32 clk_MHz, u8 clock_out_gp3)
 
 static int dib0700_jumpram(struct usb_device *udev, u32 address)
 {
-        int ret, actlen;
-        u8 buf[8] = { REQUEST_JUMPRAM, 0, 0, 0,
-                (address >> 24) & 0xff,
-                (address >> 16) & 0xff,
-                (address >> 8)  & 0xff,
-                 address        & 0xff };
+        int ret = 0, actlen;
+        u8 *buf;
+
+        buf = kmalloc(8, GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+        buf[0] = REQUEST_JUMPRAM;
+        buf[1] = 0;
+        buf[2] = 0;
+        buf[3] = 0;
+        buf[4] = (address >> 24) & 0xff;
+        buf[5] = (address >> 16) & 0xff;
+        buf[6] = (address >> 8)  & 0xff;
+        buf[7] =  address        & 0xff;
 
         if ((ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, 0x01),buf,8,&actlen,1000)) < 0) {
                 deb_fw("jumpram to 0x%x failed\n",address);
-                return ret;
+                goto out;
         }
         if (actlen != 8) {
                 deb_fw("jumpram to 0x%x failed\n",address);
-                return -EIO;
+                ret = -EIO;
+                goto out;
         }
-        return 0;
+out:
+        kfree(buf);
+        return ret;
 }
 
 int dib0700_download_firmware(struct usb_device *udev, const struct firmware *fw)
 {
         struct hexline hx;
         int pos = 0, ret, act_len, i, adap_num;
-        u8 b[16];
+        u8 *buf;
         u32 fw_version;
 
-        u8 buf[260];
+        buf = kmalloc(260, GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
 
         while ((ret = dvb_usb_get_hexline(fw, &hx, &pos)) > 0) {
                 deb_fwdata("writing to address 0x%08x (buffer: 0x%02x %02x)\n",
@@ -411,7 +454,7 @@ int dib0700_download_firmware(struct usb_device *udev, const struct firmware *fw
 
                 if (ret < 0) {
                         err("firmware download failed at %d with %d",pos,ret);
-                        return ret;
+                        goto out;
                 }
         }
 
@@ -432,8 +475,8 @@ int dib0700_download_firmware(struct usb_device *udev, const struct firmware *fw
         usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
                                   REQUEST_GET_VERSION,
                                   USB_TYPE_VENDOR | USB_DIR_IN, 0, 0,
-                                  b, sizeof(b), USB_CTRL_GET_TIMEOUT);
-        fw_version = (b[8] << 24) | (b[9] << 16) | (b[10] << 8) | b[11];
+                                  buf, 16, USB_CTRL_GET_TIMEOUT);
+        fw_version = (buf[8] << 24) | (buf[9] << 16) | (buf[10] << 8) | buf[11];
 
         /* set the buffer size - DVB-USB is allocating URB buffers
          * only after the firwmare download was successful */
@@ -451,14 +494,14 @@ int dib0700_download_firmware(struct usb_device *udev, const struct firmware *fw
                         }
                 }
         }
-
+out:
+        kfree(buf);
         return ret;
 }
 
 int dib0700_streaming_ctrl(struct dvb_usb_adapter *adap, int onoff)
 {
         struct dib0700_state *st = adap->dev->priv;
-        u8 b[4];
         int ret;
 
         if ((onoff != 0) && (st->fw_version >= 0x10201)) {
@@ -472,15 +515,17 @@ int dib0700_streaming_ctrl(struct dvb_usb_adapter *adap, int onoff)
                 }
         }
 
-        b[0] = REQUEST_ENABLE_VIDEO;
-        b[1] = (onoff << 4) | 0x00; /* this bit gives a kind of command, rather than enabling something or not */
+        st->buf[0] = REQUEST_ENABLE_VIDEO;
+        /* this bit gives a kind of command,
+         * rather than enabling something or not */
+        st->buf[1] = (onoff << 4) | 0x00;
 
         if (st->disable_streaming_master_mode == 1)
-                b[2] = 0x00;
+                st->buf[2] = 0x00;
         else
-                b[2] = 0x01 << 4; /* Master mode */
+                st->buf[2] = 0x01 << 4; /* Master mode */
 
-        b[3] = 0x00;
+        st->buf[3] = 0x00;
 
         deb_info("modifying (%d) streaming state for %d\n", onoff, adap->id);
 
@@ -499,20 +544,23 @@ int dib0700_streaming_ctrl(struct dvb_usb_adapter *adap, int onoff)
                         st->channel_state |=    1 << (3-adap->stream.props.endpoint);
         }
 
-        b[2] |= st->channel_state;
+        st->buf[2] |= st->channel_state;
 
-        deb_info("data for streaming: %x %x\n", b[1], b[2]);
+        deb_info("data for streaming: %x %x\n", st->buf[1], st->buf[2]);
 
-        return dib0700_ctrl_wr(adap->dev, b, 4);
+        return dib0700_ctrl_wr(adap->dev, st->buf, 4);
 }
 
 int dib0700_change_protocol(struct rc_dev *rc, u64 rc_type)
 {
         struct dvb_usb_device *d = rc->priv;
         struct dib0700_state *st = d->priv;
-        u8 rc_setup[3] = { REQUEST_SET_RC, 0, 0 };
         int new_proto, ret;
 
+        st->buf[0] = REQUEST_SET_RC;
+        st->buf[1] = 0;
+        st->buf[2] = 0;
+
         /* Set the IR mode */
         if (rc_type == RC_TYPE_RC5)
                 new_proto = 1;
@@ -526,9 +574,9 @@ int dib0700_change_protocol(struct rc_dev *rc, u64 rc_type)
         } else
                 return -EINVAL;
 
-        rc_setup[1] = new_proto;
+        st->buf[1] = new_proto;
 
-        ret = dib0700_ctrl_wr(d, rc_setup, sizeof(rc_setup));
+        ret = dib0700_ctrl_wr(d, st->buf, 3);
         if (ret < 0) {
                 err("ir protocol setup failed");
                 return ret;