Em Thu, 6 Oct 2016 10:27:56 -0700
Andy Lutomirski <l...@amacapital.net> escreveu:

> On Wed, Oct 5, 2016 at 11:58 AM, Mauro Carvalho Chehab
> <mche...@s-opensource.com> wrote:
> > Sorry, forgot to C/C people that are at the "Re: Problem with VMAP_STACK=y"
> > thread.
> >
> > Forwarded message:
> >
> > Date: Wed,  5 Oct 2016 15:54:18 -0300
> > From: Mauro Carvalho Chehab <mche...@s-opensource.com>
> > To: Linux Doc Mailing List <linux-...@vger.kernel.org>
> > Cc: Mauro Carvalho Chehab <mche...@s-opensource.com>, Mauro Carvalho Chehab 
> > <mche...@infradead.org>, Mauro Carvalho Chehab <mche...@kernel.org>
> > Subject: [PATCH v2] 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.
> >
> > Signed-off-by: Mauro Carvalho Chehab <mche...@s-opensource.com>
> > ---
> >
> > Added the fixups made by Johannes Stezenbach
> >
> >  drivers/media/usb/dvb-usb/cinergyT2-core.c | 45 
> > ++++++++++++++++++------------
> >  1 file changed, 27 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/media/usb/dvb-usb/cinergyT2-core.c 
> > b/drivers/media/usb/dvb-usb/cinergyT2-core.c
> > index 9fd1527494eb..8267e3777af6 100644
> > --- a/drivers/media/usb/dvb-usb/cinergyT2-core.c
> > +++ b/drivers/media/usb/dvb-usb/cinergyT2-core.c
> > @@ -41,6 +41,7 @@ DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);
> >
> >  struct cinergyt2_state {
> >         u8 rc_counter;
> > +       unsigned char data[64];
> >  };
> >
> >  /* We are missing a release hook with usb_device data */
> > @@ -50,29 +51,36 @@ 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;
> > +
> > +       st->data[0] = CINERGYT2_EP1_CONTROL_STREAM_TRANSFER;
> > +       st->data[1] = enable ? 1 : 0;
> > +
> > +       return dvb_usb_generic_rw(d, st->data, 2, st->data, 64, 0);
> >  }
> >
> >  static int cinergyt2_power_ctrl(struct dvb_usb_device *d, int enable)
> >  {  
> 
> This...
> 
> > -       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;
> > +
> > +       st->data[0] = CINERGYT2_EP1_SLEEP_MODE;  
> 
> ...does not match this:
> 
> > +       st->data[1] = enable ? 1 : 0;  
> 
> --Andy

Gah! Yes. This is what happens when coding using cut-and-paste ;)

Jörg,

Please test it with the condition reversed with the enclosed patch.

if this doesn't work, you can enable dvb-usb debug at runtime,
by loading it with debug parameter:

parm:           debug:set debugging level 
(1=info,xfer=2,pll=4,ts=8,err=16,rc=32,fw=64,mem=128,uxfer=256  (or-able)). 
(debugging is not enabled) (int)

debug=2 should show the control messages sent to the device on dmesg.

Regards,
Mauro


[PATCH] 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.

Signed-off-by: Mauro Carvalho Chehab <mche...@s-opensource.com>

diff --git a/drivers/media/usb/dvb-usb/cinergyT2-core.c 
b/drivers/media/usb/dvb-usb/cinergyT2-core.c
index 9fd1527494eb..91640c927776 100644
--- a/drivers/media/usb/dvb-usb/cinergyT2-core.c
+++ b/drivers/media/usb/dvb-usb/cinergyT2-core.c
@@ -41,6 +41,7 @@ DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);
 
 struct cinergyt2_state {
        u8 rc_counter;
+       unsigned char data[64];
 };
 
 /* We are missing a release hook with usb_device data */
@@ -50,29 +51,36 @@ 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;
+
+       st->data[0] = CINERGYT2_EP1_CONTROL_STREAM_TRANSFER;
+       st->data[1] = enable ? 1 : 0;
+
+       return dvb_usb_generic_rw(d, st->data, 2, st->data, 64, 0);
 }
 
 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;
+
+       st->data[0] = CINERGYT2_EP1_SLEEP_MODE;
+       st->data[1] = enable ? 0 : 1;
+
+       return dvb_usb_generic_rw(d, st->data, 2, st->data, 3, 0);
 }
 
 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);
+       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");
@@ -141,13 +149,14 @@ 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) {
+       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) {
@@ -166,13 +175,13 @@ static int cinergyt2_rc_query(struct dvb_usb_device *d, 
u32 *event, int *state)
        }
 
        /* 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;
 }



Thanks,
Mauro

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