V4L/DVB (5694): M920x: fix for Dposh devices

Make sure devices manufactured by Dposh are not affected by previous hw 
pid filtering changes

Doing so might crash it.

Signed-off-by: Aapo Tahkola <aet@rasterburn.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 22 insertions, 16 deletions

diff --git a/drivers/media/dvb/dvb-usb/m920x.c b/drivers/media/dvb/dvb-usb/m920x.c
index 350cdc90b9c8..1156b7df7978 100644
--- a/drivers/media/dvb/dvb-usb/m920x.c
+++ b/drivers/media/dvb/dvb-usb/m920x.c
@@ -59,7 +59,7 @@ static inline int m920x_write(struct usb_device *udev, u8 request,
 
 static int m920x_init(struct dvb_usb_device *d, struct m920x_inits *rc_seq)
 {
-        int ret = 0, i, epi;
+        int ret = 0, i, epi, flags = 0;
         int adap_enabled[M9206_MAX_ADAPTERS] = { 0 };
 
         /* Remote controller init. */
@@ -79,26 +79,32 @@ static int m920x_init(struct dvb_usb_device *d, struct m920x_inits *rc_seq)
                 deb("Initialising remote control success\n");
         }
 
-        for (i = 0; i < d->props.num_adapters; i++) {
-                epi = d->adapter[i].props.stream.endpoint - 0x81;
+        for (i = 0; i < d->props.num_adapters; i++)
+                flags |= d->adapter[i].props.caps;
 
-                if (epi < 0 || epi >= M9206_MAX_ADAPTERS) {
-                        printk(KERN_INFO "m920x: Unexpected adapter endpoint!\n");
-                        return -EINVAL;
-                }
+        /* Some devices(Dposh) might crash if we attempt touch at all. */
+        if (flags & DVB_USB_ADAP_HAS_PID_FILTER) {
+                for (i = 0; i < d->props.num_adapters; i++) {
+                        epi = d->adapter[i].props.stream.endpoint - 0x81;
 
-                adap_enabled[epi] = 1;
-        }
+                        if (epi < 0 || epi >= M9206_MAX_ADAPTERS) {
+                                printk(KERN_INFO "m920x: Unexpected adapter endpoint!\n");
+                                return -EINVAL;
+                        }
 
-        for (i = 0; i < M9206_MAX_ADAPTERS; i++) {
-                if (adap_enabled[i])
-                        continue;
+                        adap_enabled[epi] = 1;
+                }
 
-                if ((ret = m920x_set_filter(d, 0x81 + i, 0, 0x0)) != 0)
-                        return ret;
+                for (i = 0; i < M9206_MAX_ADAPTERS; i++) {
+                        if (adap_enabled[i])
+                                continue;
 
-                if ((ret = m920x_set_filter(d, 0x81 + i, 0, 0x02f5)) != 0)
-                        return ret;
+                        if ((ret = m920x_set_filter(d, 0x81 + i, 0, 0x0)) != 0)
+                                return ret;
+
+                        if ((ret = m920x_set_filter(d, 0x81 + i, 0, 0x02f5)) != 0)
+                                return ret;
+                }
         }
 
         return ret;