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[media] em28xx: improve USB endpoint logic, also use bulk transfers
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The current enpoint logic ignores all bulk endpoints and uses
a fixed mapping between endpint addresses and the supported
data stream types (analog/audio/DVB):
  Ep 0x82, isoc	=> analog
  Ep 0x83, isoc	=> audio
  Ep 0x84, isoc	=> DVB
Now that the code can also do bulk transfers, the endpoint
logic has to be extended to also consider bulk endpoints.
The new logic preserves backwards compatibility and reflects
the endpoint configurations we have seen so far:
  Ep 0x82, isoc		=> analog
  Ep 0x82, bulk		=> analog
  Ep 0x83, isoc*	=> audio
  Ep 0x84, isoc		=> digital
  Ep 0x84, bulk		=> analog or digital**
 (*: audio should always be isoc)
 (**: analog, if ep 0x82 is isoc, otherwise digital)

[mchehab@redhat.com: Fix a CodingStyle issue: don't break strings
 into separate lines]

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
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Frank Schaefer authored and Mauro Carvalho Chehab committed Dec 22, 2012
1 parent c8e9d95 commit c647a91
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Showing 6 changed files with 147 additions and 40 deletions.
95 changes: 77 additions & 18 deletions drivers/media/usb/em28xx/em28xx-cards.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@
Markus Rechberger <mrechberger@gmail.com>
Mauro Carvalho Chehab <mchehab@infradead.org>
Sascha Sommer <saschasommer@freenet.de>
Copyright (C) 2012 Frank Schäfer <fschaefer.oss@googlemail.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
Expand Down Expand Up @@ -3209,26 +3210,67 @@ static int em28xx_usb_probe(struct usb_interface *interface,
if (udev->speed == USB_SPEED_HIGH)
size = size * hb_mult(sizedescr);

if (usb_endpoint_xfer_isoc(e) &&
usb_endpoint_dir_in(e)) {
if (usb_endpoint_dir_in(e)) {
switch (e->bEndpointAddress) {
case EM28XX_EP_AUDIO:
has_audio = true;
break;
case EM28XX_EP_ANALOG:
case 0x82:
has_video = true;
dev->alt_max_pkt_size_isoc[i] = size;
if (usb_endpoint_xfer_isoc(e)) {
dev->analog_ep_isoc =
e->bEndpointAddress;
dev->alt_max_pkt_size_isoc[i] = size;
} else if (usb_endpoint_xfer_bulk(e)) {
dev->analog_ep_bulk =
e->bEndpointAddress;
}
break;
case 0x83:
if (usb_endpoint_xfer_isoc(e)) {
has_audio = true;
} else {
printk(KERN_INFO DRIVER_NAME
": error: skipping audio endpoint 0x83, because it uses bulk transfers !\n");
}
break;
case EM28XX_EP_DIGITAL:
has_dvb = true;
if (size > dev->dvb_max_pkt_size_isoc) {
dev->dvb_max_pkt_size_isoc =
size;
dev->dvb_alt_isoc = i;
case 0x84:
if (has_video &&
(usb_endpoint_xfer_bulk(e))) {
dev->analog_ep_bulk =
e->bEndpointAddress;
} else {
has_dvb = true;
if (usb_endpoint_xfer_isoc(e)) {
dev->dvb_ep_isoc = e->bEndpointAddress;
if (size > dev->dvb_max_pkt_size_isoc) {
dev->dvb_max_pkt_size_isoc = size;
dev->dvb_alt_isoc = i;
}
} else {
dev->dvb_ep_bulk = e->bEndpointAddress;
}
}
break;
}
}
/* NOTE:
* Old logic with support for isoc transfers only was:
* 0x82 isoc => analog
* 0x83 isoc => audio
* 0x84 isoc => digital
*
* New logic with support for bulk transfers
* 0x82 isoc => analog
* 0x82 bulk => analog
* 0x83 isoc* => audio
* 0x84 isoc => digital
* 0x84 bulk => analog or digital**
* (*: audio should always be isoc)
* (**: analog, if ep 0x82 is isoc, otherwise digital)
*
* The new logic preserves backwards compatibility and
* reflects the endpoint configurations we have seen
* so far. But there might be devices for which this
* logic is not sufficient...
*/
}
}

Expand Down Expand Up @@ -3289,6 +3331,12 @@ static int em28xx_usb_probe(struct usb_interface *interface,
goto err_free;
}

/* Select USB transfer types to use */
if (has_video && !dev->analog_ep_isoc)
dev->analog_xfer_bulk = 1;
if (has_dvb && !dev->dvb_ep_isoc)
dev->dvb_xfer_bulk = 1;

snprintf(dev->name, sizeof(dev->name), "em28xx #%d", nr);
dev->devno = nr;
dev->model = id->driver_info;
Expand Down Expand Up @@ -3323,12 +3371,23 @@ static int em28xx_usb_probe(struct usb_interface *interface,
}

if (has_dvb) {
/* pre-allocate DVB isoc transfer buffers */
retval = em28xx_alloc_urbs(dev, EM28XX_DIGITAL_MODE, 0,
EM28XX_DVB_NUM_BUFS,
dev->dvb_max_pkt_size_isoc,
EM28XX_DVB_NUM_ISOC_PACKETS);
/* pre-allocate DVB usb transfer buffers */
if (dev->dvb_xfer_bulk) {
retval = em28xx_alloc_urbs(dev, EM28XX_DIGITAL_MODE,
dev->dvb_xfer_bulk,
EM28XX_DVB_NUM_BUFS,
512,
EM28XX_DVB_BULK_PACKET_MULTIPLIER);
} else {
retval = em28xx_alloc_urbs(dev, EM28XX_DIGITAL_MODE,
dev->dvb_xfer_bulk,
EM28XX_DVB_NUM_BUFS,
dev->dvb_max_pkt_size_isoc,
EM28XX_DVB_NUM_ISOC_PACKETS);
}
if (retval) {
printk(DRIVER_NAME
": Failed to pre-allocate USB transfer buffers for DVB.\n");
goto unlock_and_free;
}
}
Expand Down
32 changes: 26 additions & 6 deletions drivers/media/usb/em28xx/em28xx-core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -847,11 +847,13 @@ int em28xx_set_alternate(struct em28xx *dev)
if (dev->alt != prev_alt) {
if (dev->analog_xfer_bulk) {
dev->max_pkt_size = 512; /* USB 2.0 spec */
dev->packet_multiplier = EM28XX_BULK_PACKET_MULTIPLIER;
} else { /* isoc */
em28xx_coredbg("minimum isoc packet size: %u (alt=%d)\n",
min_pkt_size, dev->alt);
dev->max_pkt_size =
dev->alt_max_pkt_size_isoc[dev->alt];
dev->packet_multiplier = EM28XX_NUM_ISOC_PACKETS;
}
em28xx_coredbg("setting alternate %d with wMaxPacketSize=%u\n",
dev->alt, dev->max_pkt_size);
Expand Down Expand Up @@ -1054,10 +1056,28 @@ int em28xx_alloc_urbs(struct em28xx *dev, enum em28xx_mode mode, int xfer_bulk,

em28xx_isocdbg("em28xx: called em28xx_alloc_isoc in mode %d\n", mode);

if (mode == EM28XX_DIGITAL_MODE)
/* Check mode and if we have an endpoint for the selected
transfer type, select buffer */
if (mode == EM28XX_DIGITAL_MODE) {
if ((xfer_bulk && !dev->dvb_ep_bulk) ||
(!xfer_bulk && !dev->dvb_ep_isoc)) {
em28xx_errdev("no endpoint for DVB mode and transfer type %d\n",
xfer_bulk > 0);
return -EINVAL;
}
usb_bufs = &dev->usb_ctl.digital_bufs;
else
} else if (mode == EM28XX_ANALOG_MODE) {
if ((xfer_bulk && !dev->analog_ep_bulk) ||
(!xfer_bulk && !dev->analog_ep_isoc)) {
em28xx_errdev("no endpoint for analog mode and transfer type %d\n",
xfer_bulk > 0);
return -EINVAL;
}
usb_bufs = &dev->usb_ctl.analog_bufs;
} else {
em28xx_errdev("invalid mode selected\n");
return -EINVAL;
}

/* De-allocates all pending stuff */
em28xx_uninit_usb_xfer(dev, mode);
Expand Down Expand Up @@ -1113,17 +1133,17 @@ int em28xx_alloc_urbs(struct em28xx *dev, enum em28xx_mode mode, int xfer_bulk,
if (xfer_bulk) { /* bulk */
pipe = usb_rcvbulkpipe(dev->udev,
mode == EM28XX_ANALOG_MODE ?
EM28XX_EP_ANALOG :
EM28XX_EP_DIGITAL);
dev->analog_ep_bulk :
dev->dvb_ep_bulk);
usb_fill_bulk_urb(urb, dev->udev, pipe,
usb_bufs->transfer_buffer[i], sb_size,
em28xx_irq_callback, dev);
urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
} else { /* isoc */
pipe = usb_rcvisocpipe(dev->udev,
mode == EM28XX_ANALOG_MODE ?
EM28XX_EP_ANALOG :
EM28XX_EP_DIGITAL);
dev->analog_ep_isoc :
dev->dvb_ep_isoc);
usb_fill_int_urb(urb, dev->udev, pipe,
usb_bufs->transfer_buffer[i], sb_size,
em28xx_irq_callback, dev, 1);
Expand Down
34 changes: 24 additions & 10 deletions drivers/media/usb/em28xx/em28xx-dvb.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -176,25 +176,39 @@ static int em28xx_start_streaming(struct em28xx_dvb *dvb)
{
int rc;
struct em28xx *dev = dvb->adapter.priv;
int max_dvb_packet_size;
int dvb_max_packet_size, packet_multiplier, dvb_alt;

if (dev->dvb_xfer_bulk) {
if (!dev->dvb_ep_bulk)
return -ENODEV;
dvb_max_packet_size = 512; /* USB 2.0 spec */
packet_multiplier = EM28XX_DVB_BULK_PACKET_MULTIPLIER;
dvb_alt = 0;
} else { /* isoc */
if (!dev->dvb_ep_isoc)
return -ENODEV;
dvb_max_packet_size = dev->dvb_max_pkt_size_isoc;
if (dvb_max_packet_size < 0)
return dvb_max_packet_size;
packet_multiplier = EM28XX_DVB_NUM_ISOC_PACKETS;
dvb_alt = dev->dvb_alt_isoc;
}

usb_set_interface(dev->udev, 0, dev->dvb_alt_isoc);
usb_set_interface(dev->udev, 0, dvb_alt);
rc = em28xx_set_mode(dev, EM28XX_DIGITAL_MODE);
if (rc < 0)
return rc;

max_dvb_packet_size = dev->dvb_max_pkt_size_isoc;
if (max_dvb_packet_size < 0)
return max_dvb_packet_size;
dprintk(1, "Using %d buffers each with %d x %d bytes\n",
EM28XX_DVB_NUM_BUFS,
EM28XX_DVB_NUM_ISOC_PACKETS,
max_dvb_packet_size);
packet_multiplier,
dvb_max_packet_size);

return em28xx_init_usb_xfer(dev, EM28XX_DIGITAL_MODE, 0,
return em28xx_init_usb_xfer(dev, EM28XX_DIGITAL_MODE,
dev->dvb_xfer_bulk,
EM28XX_DVB_NUM_BUFS,
max_dvb_packet_size,
EM28XX_DVB_NUM_ISOC_PACKETS,
dvb_max_packet_size,
packet_multiplier,
em28xx_dvb_urb_data_copy);
}

Expand Down
4 changes: 2 additions & 2 deletions drivers/media/usb/em28xx/em28xx-reg.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -13,9 +13,9 @@
#define EM_GPO_3 (1 << 3)

/* em28xx endpoints */
#define EM28XX_EP_ANALOG 0x82
/* 0x82: (always ?) analog */
#define EM28XX_EP_AUDIO 0x83
#define EM28XX_EP_DIGITAL 0x84
/* 0x84: digital or analog */

/* em2800 registers */
#define EM2800_R08_AUDIOSRC 0x08
Expand Down
10 changes: 6 additions & 4 deletions drivers/media/usb/em28xx/em28xx-video.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -788,16 +788,18 @@ buffer_prepare(struct videobuf_queue *vq, struct videobuf_buffer *vb,

if (urb_init) {
if (em28xx_vbi_supported(dev) == 1)
rc = em28xx_init_usb_xfer(dev, EM28XX_ANALOG_MODE, 0,
rc = em28xx_init_usb_xfer(dev, EM28XX_ANALOG_MODE,
dev->analog_xfer_bulk,
EM28XX_NUM_BUFS,
dev->max_pkt_size,
EM28XX_NUM_ISOC_PACKETS,
dev->packet_multiplier,
em28xx_urb_data_copy_vbi);
else
rc = em28xx_init_usb_xfer(dev, EM28XX_ANALOG_MODE, 0,
rc = em28xx_init_usb_xfer(dev, EM28XX_ANALOG_MODE,
dev->analog_xfer_bulk,
EM28XX_NUM_BUFS,
dev->max_pkt_size,
EM28XX_NUM_ISOC_PACKETS,
dev->packet_multiplier,
em28xx_urb_data_copy);
if (rc < 0)
goto fail;
Expand Down
12 changes: 12 additions & 0 deletions drivers/media/usb/em28xx/em28xx.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -165,6 +165,12 @@
#define EM28XX_NUM_ISOC_PACKETS 64
#define EM28XX_DVB_NUM_ISOC_PACKETS 64

/* bulk transfers: transfer buffer size = packet size * packet multiplier
USB 2.0 spec says bulk packet size is always 512 bytes
*/
#define EM28XX_BULK_PACKET_MULTIPLIER 384
#define EM28XX_DVB_BULK_PACKET_MULTIPLIER 384

#define EM28XX_INTERLACED_DEFAULT 1

/*
Expand Down Expand Up @@ -584,8 +590,14 @@ struct em28xx {

/* usb transfer */
struct usb_device *udev; /* the usb device */
u8 analog_ep_isoc; /* address of isoc endpoint for analog */
u8 analog_ep_bulk; /* address of bulk endpoint for analog */
u8 dvb_ep_isoc; /* address of isoc endpoint for DVB */
u8 dvb_ep_bulk; /* address of bulk endpoint for DVC */
int alt; /* alternate setting */
int max_pkt_size; /* max packet size of the selected ep at alt */
int packet_multiplier; /* multiplier for wMaxPacketSize, used for
URB buffer size definition */
int num_alt; /* number of alternative settings */
unsigned int *alt_max_pkt_size_isoc; /* array of isoc wMaxPacketSize */
unsigned int analog_xfer_bulk:1; /* use bulk instead of isoc
Expand Down

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