[media] cinergyT2-core: don't do DMA on stack

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>

diff --git a/drivers/media/usb/dvb-usb/cinergyT2-core.c b/drivers/media/usb/dvb-usb/cinergyT2-core.c
index 9fd1527494ebd65ab200c38f13a20e28330034a1..d85c0c4d40421c59b7779e7982a6ca5fe9d81f81 100644 (file)
--- a/drivers/media/usb/dvb-usb/cinergyT2-core.c
+++ b/drivers/media/usb/dvb-usb/cinergyT2-core.c
@@ -41,6 +41,8 @@ DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);
 
 struct cinergyt2_state {
        u8 rc_counter;
+       unsigned char data[64];
+       struct mutex data_mutex;
 };
 
 /* We are missing a release hook with usb_device data */
@@ -50,33 +52,52 @@ static struct dvb_usb_device_properties cinergyt2_properties;
 
 static int cinergyt2_streaming_ctrl(struct dvb_usb_adapter *adap, int enable)
 {
-       char buf[] = { CINERGYT2_EP1_CONTROL_STREAM_TRANSFER, enable ? 1 : 0 };
-       char result[64];
-       return dvb_usb_generic_rw(adap->dev, buf, sizeof(buf), result,
-                               sizeof(result), 0);
+       struct dvb_usb_device *d = adap->dev;
+       struct cinergyt2_state *st = d->priv;
+       int ret;
+
+       mutex_lock(&st->data_mutex);
+       st->data[0] = CINERGYT2_EP1_CONTROL_STREAM_TRANSFER;
+       st->data[1] = enable ? 1 : 0;
+
+       ret = dvb_usb_generic_rw(d, st->data, 2, st->data, 64, 0);
+       mutex_unlock(&st->data_mutex);
+
+       return ret;
 }
 
 static int cinergyt2_power_ctrl(struct dvb_usb_device *d, int enable)
 {
-       char buf[] = { CINERGYT2_EP1_SLEEP_MODE, enable ? 0 : 1 };
-       char state[3];
-       return dvb_usb_generic_rw(d, buf, sizeof(buf), state, sizeof(state), 0);
+       struct cinergyt2_state *st = d->priv;
+       int ret;
+
+       mutex_lock(&st->data_mutex);
+       st->data[0] = CINERGYT2_EP1_SLEEP_MODE;
+       st->data[1] = enable ? 0 : 1;
+
+       ret = dvb_usb_generic_rw(d, st->data, 2, st->data, 3, 0);
+       mutex_unlock(&st->data_mutex);
+
+       return ret;
 }
 
 static int cinergyt2_frontend_attach(struct dvb_usb_adapter *adap)
 {
-       char query[] = { CINERGYT2_EP1_GET_FIRMWARE_VERSION };
-       char state[3];
+       struct dvb_usb_device *d = adap->dev;
+       struct cinergyt2_state *st = d->priv;
        int ret;
 
        adap->fe_adap[0].fe = cinergyt2_fe_attach(adap->dev);
 
-       ret = dvb_usb_generic_rw(adap->dev, query, sizeof(query), state,
-                               sizeof(state), 0);
+       mutex_lock(&st->data_mutex);
+       st->data[0] = CINERGYT2_EP1_GET_FIRMWARE_VERSION;
+
+       ret = dvb_usb_generic_rw(d, st->data, 1, st->data, 3, 0);
        if (ret < 0) {
                deb_rc("cinergyt2_power_ctrl() Failed to retrieve sleep "
                        "state info\n");
        }
+       mutex_unlock(&st->data_mutex);
 
        /* Copy this pointer as we are gonna need it in the release phase */
        cinergyt2_usb_device = adap->dev;
@@ -141,13 +162,16 @@ static int repeatable_keys[] = {
 static int cinergyt2_rc_query(struct dvb_usb_device *d, u32 *event, int *state)
 {
        struct cinergyt2_state *st = d->priv;
-       u8 key[5] = {0, 0, 0, 0, 0}, cmd = CINERGYT2_EP1_GET_RC_EVENTS;
        int i;
 
        *state = REMOTE_NO_KEY_PRESSED;
 
-       dvb_usb_generic_rw(d, &cmd, 1, key, sizeof(key), 0);
-       if (key[4] == 0xff) {
+       mutex_lock(&st->data_mutex);
+       st->data[0] = CINERGYT2_EP1_GET_RC_EVENTS;
+
+       dvb_usb_generic_rw(d, st->data, 1, st->data, 5, 0);
+
+       if (st->data[4] == 0xff) {
                /* key repeat */
                st->rc_counter++;
                if (st->rc_counter > RC_REPEAT_DELAY) {
@@ -157,31 +181,45 @@ static int cinergyt2_rc_query(struct dvb_usb_device *d, u32 *event, int *state)
                                        *event = d->last_event;
                                        deb_rc("repeat key, event %x\n",
                                                   *event);
-                                       return 0;
+                                       goto ret;
                                }
                        }
                        deb_rc("repeated key (non repeatable)\n");
                }
-               return 0;
+               goto ret;
        }
 
        /* hack to pass checksum on the custom field */
-       key[2] = ~key[1];
-       dvb_usb_nec_rc_key_to_event(d, key, event, state);
-       if (key[0] != 0) {
+       st->data[2] = ~st->data[1];
+       dvb_usb_nec_rc_key_to_event(d, st->data, event, state);
+       if (st->data[0] != 0) {
                if (*event != d->last_event)
                        st->rc_counter = 0;
 
-               deb_rc("key: %*ph\n", 5, key);
+               deb_rc("key: %*ph\n", 5, st->data);
        }
-       return 0;
+
+ret:
+       mutex_unlock(&st->data_mutex);
+       return ret;
 }
 
 static int cinergyt2_usb_probe(struct usb_interface *intf,
                                const struct usb_device_id *id)
 {
-       return dvb_usb_device_init(intf, &cinergyt2_properties,
-                                       THIS_MODULE, NULL, adapter_nr);
+       struct dvb_usb_device *d;
+       struct cinergyt2_state *st;
+       int ret;
+
+       ret = dvb_usb_device_init(intf, &cinergyt2_properties,
+                                 THIS_MODULE, &d, adapter_nr);
+       if (ret < 0)
+               return ret;
+
+       st = d->priv;
+       mutex_init(&st->data_mutex);
+
+       return 0;
 }