* [PATCH] Alternate setting 1 must be selected for interface 0 on the model that I received. Else the rest is identical.
@ 2011-05-23 14:37 Hans Petter Selasky
2011-05-23 18:14 ` Mauro Carvalho Chehab
0 siblings, 1 reply; 9+ messages in thread
From: Hans Petter Selasky @ 2011-05-23 14:37 UTC (permalink / raw)
To: linux-media@vger.kernel.org; +Cc: Mauro Carvalho Chehab
[-- Attachment #1: Type: text/plain, Size: 6 bytes --]
--HPS
[-- Attachment #2: dvb-usb-0016.patch --]
[-- Type: text/x-patch, Size: 1280 bytes --]
From 3cf61d6a77b22f58471188cd0e7e3dc6c3a29b0b Mon Sep 17 00:00:00 2001
From: Hans Petter Selasky <hselasky@c2i.net>
Date: Mon, 23 May 2011 16:36:55 +0200
Subject: [PATCH] Alternate setting 1 must be selected for interface 0 on the model that I received. Else the rest is identical.
Signed-off-by: Hans Petter Selasky <hselasky@c2i.net>
---
drivers/media/dvb/ttusb-budget/dvb-ttusb-budget.c | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/drivers/media/dvb/ttusb-budget/dvb-ttusb-budget.c b/drivers/media/dvb/ttusb-budget/dvb-ttusb-budget.c
index cbe2f0d..38a7d03 100644
--- a/drivers/media/dvb/ttusb-budget/dvb-ttusb-budget.c
+++ b/drivers/media/dvb/ttusb-budget/dvb-ttusb-budget.c
@@ -971,6 +971,14 @@ static int ttusb_stop_feed(struct dvb_demux_feed *dvbdmxfeed)
static int ttusb_setup_interfaces(struct ttusb *ttusb)
{
+ /*
+ * Try to select alternate setting 1 for first interface. If
+ * that does not work, restore to alternate setting 0.
+ */
+ if (usb_set_interface(ttusb->dev, 0, 1) < 0)
+ usb_set_interface(ttusb->dev, 0, 0);
+
+ /* Select alternate setting 1 for second interface. */
usb_set_interface(ttusb->dev, 1, 1);
ttusb->bulk_out_pipe = usb_sndbulkpipe(ttusb->dev, 1);
--
1.7.1.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] Alternate setting 1 must be selected for interface 0 on the model that I received. Else the rest is identical.
2011-05-23 14:37 [PATCH] Alternate setting 1 must be selected for interface 0 on the model that I received. Else the rest is identical Hans Petter Selasky
@ 2011-05-23 18:14 ` Mauro Carvalho Chehab
2011-05-23 18:48 ` Hans Petter Selasky
0 siblings, 1 reply; 9+ messages in thread
From: Mauro Carvalho Chehab @ 2011-05-23 18:14 UTC (permalink / raw)
To: Hans Petter Selasky; +Cc: linux-media@vger.kernel.org
Em 23-05-2011 11:37, Hans Petter Selasky escreveu:
> -HPS
>
>
> dvb-usb-0016.patch
>
>
> From 3cf61d6a77b22f58471188cd0e7e3dc6c3a29b0b Mon Sep 17 00:00:00 2001
> From: Hans Petter Selasky <hselasky@c2i.net>
> Date: Mon, 23 May 2011 16:36:55 +0200
> Subject: [PATCH] Alternate setting 1 must be selected for interface 0 on the model that I received. Else the rest is identical.
>
> Signed-off-by: Hans Petter Selasky <hselasky@c2i.net>
> ---
> drivers/media/dvb/ttusb-budget/dvb-ttusb-budget.c | 8 ++++++++
> 1 files changed, 8 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/media/dvb/ttusb-budget/dvb-ttusb-budget.c b/drivers/media/dvb/ttusb-budget/dvb-ttusb-budget.c
> index cbe2f0d..38a7d03 100644
> --- a/drivers/media/dvb/ttusb-budget/dvb-ttusb-budget.c
> +++ b/drivers/media/dvb/ttusb-budget/dvb-ttusb-budget.c
> @@ -971,6 +971,14 @@ static int ttusb_stop_feed(struct dvb_demux_feed *dvbdmxfeed)
>
> static int ttusb_setup_interfaces(struct ttusb *ttusb)
> {
> + /*
> + * Try to select alternate setting 1 for first interface. If
> + * that does not work, restore to alternate setting 0.
> + */
> + if (usb_set_interface(ttusb->dev, 0, 1) < 0)
> + usb_set_interface(ttusb->dev, 0, 0);
> +
> + /* Select alternate setting 1 for second interface. */
> usb_set_interface(ttusb->dev, 1, 1);
>
> ttusb->bulk_out_pipe = usb_sndbulkpipe(ttusb->dev, 1);
> -- 1.7.1.1
I don't have any ttusb device here, but I doubt that this would work.
Alternates should be selected depending on the bandwidth needed. The right way
is to write some logic that will get the maximum packet size for each mode, between the
alternates that provide the type of transfer (Bulk or ISOC) accepted by the driver.
You may take a look at staging/tm6000 or at drivers/media/video/em28xx or at
drivers/media/video/gspca to see a few examples on how to do that. IMHO, the
alternates selection code at tm6000 is in better shape than the others I know.
Cheers,
Mauro.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Alternate setting 1 must be selected for interface 0 on the model that I received. Else the rest is identical.
2011-05-23 18:14 ` Mauro Carvalho Chehab
@ 2011-05-23 18:48 ` Hans Petter Selasky
2011-05-23 19:06 ` Mauro Carvalho Chehab
0 siblings, 1 reply; 9+ messages in thread
From: Hans Petter Selasky @ 2011-05-23 18:48 UTC (permalink / raw)
To: Mauro Carvalho Chehab; +Cc: linux-media@vger.kernel.org
[-- Attachment #1: Type: Text/Plain, Size: 881 bytes --]
On Monday 23 May 2011 20:14:45 Mauro Carvalho Chehab wrote:
> Em 23-05-2011 11:37, Hans Petter Selasky escreveu:
>
> I don't have any ttusb device here, but I doubt that this would work.
Hi,
It is already tested and works fine.
What I see is that interface 1 does not have an alternate setting like the
driver code expects, while interface 0 does. So it is the opposite of what the
driver expects. Maybe the manufacturer changed something. Endpoints are still
the same.
Please find attached an USB descriptor dump from this device.
>
> Alternates should be selected depending on the bandwidth needed. The right
> way is to write some logic that will get the maximum packet size for each
> mode, between the alternates that provide the type of transfer (Bulk or
> ISOC) accepted by the driver.
Right, but this driver doesn't do this. It only selects a working one.
--HPS
[-- Attachment #2: descriptors.txt --]
[-- Type: text/plain, Size: 16285 bytes --]
ugen6.2: <WinTV NOVA-t USB Hauppauge> at usbus6, cfg=0 md=HOST spd=FULL (12Mbps) pwr=ON
bLength = 0x0012
bDescriptorType = 0x0001
bcdUSB = 0x0100
bDeviceClass = 0x0000
bDeviceSubClass = 0x0000
bDeviceProtocol = 0x0000
bMaxPacketSize0 = 0x0008
idVendor = 0x0b48
idProduct = 0x1005
bcdDevice = 0x0100
iManufacturer = 0x0001 <Hauppauge>
iProduct = 0x0002 <WinTV NOVA-t USB>
iSerialNumber = 0x0000 <no string>
bNumConfigurations = 0x0001
Configuration index 0
bLength = 0x0009
bDescriptorType = 0x0002
wTotalLength = 0x019f
bNumInterfaces = 0x0002
bConfigurationValue = 0x0001
iConfiguration = 0x0004 <Config0>
bmAttributes = 0x0040
bMaxPower = 0x0000
Interface 0
bLength = 0x0009
bDescriptorType = 0x0004
bInterfaceNumber = 0x0000
bAlternateSetting = 0x0000
bNumEndpoints = 0x0003
bInterfaceClass = 0x0000
bInterfaceSubClass = 0x0000
bInterfaceProtocol = 0x0000
iInterface = 0x0000 <no string>
Endpoint 0
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0081 <IN>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 1
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0001 <OUT>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 2
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0082 <IN>
bmAttributes = 0x0001 <ISOCHRONOUS>
wMaxPacketSize = 0x0000
bInterval = 0x0001
bRefresh = 0x0000
bSynchAddress = 0x0000
Interface 0 Alt 1
bLength = 0x0009
bDescriptorType = 0x0004
bInterfaceNumber = 0x0000
bAlternateSetting = 0x0001
bNumEndpoints = 0x0003
bInterfaceClass = 0x0000
bInterfaceSubClass = 0x0000
bInterfaceProtocol = 0x0000
iInterface = 0x0000 <no string>
Endpoint 0
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0081 <IN>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 1
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0001 <OUT>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 2
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0082 <IN>
bmAttributes = 0x0001 <ISOCHRONOUS>
wMaxPacketSize = 0x0390
bInterval = 0x0001
bRefresh = 0x0000
bSynchAddress = 0x0000
Interface 0 Alt 2
bLength = 0x0009
bDescriptorType = 0x0004
bInterfaceNumber = 0x0000
bAlternateSetting = 0x0002
bNumEndpoints = 0x0003
bInterfaceClass = 0x0000
bInterfaceSubClass = 0x0000
bInterfaceProtocol = 0x0000
iInterface = 0x0000 <no string>
Endpoint 0
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0081 <IN>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 1
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0001 <OUT>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 2
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0082 <IN>
bmAttributes = 0x0001 <ISOCHRONOUS>
wMaxPacketSize = 0x0360
bInterval = 0x0001
bRefresh = 0x0000
bSynchAddress = 0x0000
Interface 0 Alt 3
bLength = 0x0009
bDescriptorType = 0x0004
bInterfaceNumber = 0x0000
bAlternateSetting = 0x0003
bNumEndpoints = 0x0003
bInterfaceClass = 0x0000
bInterfaceSubClass = 0x0000
bInterfaceProtocol = 0x0000
iInterface = 0x0000 <no string>
Endpoint 0
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0081 <IN>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 1
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0001 <OUT>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 2
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0082 <IN>
bmAttributes = 0x0001 <ISOCHRONOUS>
wMaxPacketSize = 0x0338
bInterval = 0x0001
bRefresh = 0x0000
bSynchAddress = 0x0000
Interface 0 Alt 4
bLength = 0x0009
bDescriptorType = 0x0004
bInterfaceNumber = 0x0000
bAlternateSetting = 0x0004
bNumEndpoints = 0x0003
bInterfaceClass = 0x0000
bInterfaceSubClass = 0x0000
bInterfaceProtocol = 0x0000
iInterface = 0x0000 <no string>
Endpoint 0
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0081 <IN>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 1
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0001 <OUT>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 2
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0082 <IN>
bmAttributes = 0x0001 <ISOCHRONOUS>
wMaxPacketSize = 0x02d8
bInterval = 0x0001
bRefresh = 0x0000
bSynchAddress = 0x0000
Interface 0 Alt 5
bLength = 0x0009
bDescriptorType = 0x0004
bInterfaceNumber = 0x0000
bAlternateSetting = 0x0005
bNumEndpoints = 0x0003
bInterfaceClass = 0x0000
bInterfaceSubClass = 0x0000
bInterfaceProtocol = 0x0000
iInterface = 0x0000 <no string>
Endpoint 0
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0081 <IN>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 1
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0001 <OUT>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 2
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0082 <IN>
bmAttributes = 0x0001 <ISOCHRONOUS>
wMaxPacketSize = 0x0278
bInterval = 0x0001
bRefresh = 0x0000
bSynchAddress = 0x0000
Interface 0 Alt 6
bLength = 0x0009
bDescriptorType = 0x0004
bInterfaceNumber = 0x0000
bAlternateSetting = 0x0006
bNumEndpoints = 0x0003
bInterfaceClass = 0x0000
bInterfaceSubClass = 0x0000
bInterfaceProtocol = 0x0000
iInterface = 0x0000 <no string>
Endpoint 0
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0081 <IN>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 1
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0001 <OUT>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 2
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0082 <IN>
bmAttributes = 0x0001 <ISOCHRONOUS>
wMaxPacketSize = 0x0220
bInterval = 0x0001
bRefresh = 0x0000
bSynchAddress = 0x0000
Interface 0 Alt 7
bLength = 0x0009
bDescriptorType = 0x0004
bInterfaceNumber = 0x0000
bAlternateSetting = 0x0007
bNumEndpoints = 0x0003
bInterfaceClass = 0x0000
bInterfaceSubClass = 0x0000
bInterfaceProtocol = 0x0000
iInterface = 0x0000 <no string>
Endpoint 0
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0081 <IN>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 1
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0001 <OUT>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 2
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0082 <IN>
bmAttributes = 0x0001 <ISOCHRONOUS>
wMaxPacketSize = 0x01c0
bInterval = 0x0001
bRefresh = 0x0000
bSynchAddress = 0x0000
Interface 0 Alt 8
bLength = 0x0009
bDescriptorType = 0x0004
bInterfaceNumber = 0x0000
bAlternateSetting = 0x0008
bNumEndpoints = 0x0003
bInterfaceClass = 0x0000
bInterfaceSubClass = 0x0000
bInterfaceProtocol = 0x0000
iInterface = 0x0000 <no string>
Endpoint 0
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0081 <IN>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 1
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0001 <OUT>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 2
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0082 <IN>
bmAttributes = 0x0001 <ISOCHRONOUS>
wMaxPacketSize = 0x0160
bInterval = 0x0001
bRefresh = 0x0000
bSynchAddress = 0x0000
Interface 0 Alt 9
bLength = 0x0009
bDescriptorType = 0x0004
bInterfaceNumber = 0x0000
bAlternateSetting = 0x0009
bNumEndpoints = 0x0003
bInterfaceClass = 0x0000
bInterfaceSubClass = 0x0000
bInterfaceProtocol = 0x0000
iInterface = 0x0000 <no string>
Endpoint 0
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0081 <IN>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 1
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0001 <OUT>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 2
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0082 <IN>
bmAttributes = 0x0001 <ISOCHRONOUS>
wMaxPacketSize = 0x0100
bInterval = 0x0001
bRefresh = 0x0000
bSynchAddress = 0x0000
Interface 0 Alt 10
bLength = 0x0009
bDescriptorType = 0x0004
bInterfaceNumber = 0x0000
bAlternateSetting = 0x000a
bNumEndpoints = 0x0003
bInterfaceClass = 0x0000
bInterfaceSubClass = 0x0000
bInterfaceProtocol = 0x0000
iInterface = 0x0000 <no string>
Endpoint 0
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0081 <IN>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 1
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0001 <OUT>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 2
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0082 <IN>
bmAttributes = 0x0001 <ISOCHRONOUS>
wMaxPacketSize = 0x00c0
bInterval = 0x0001
bRefresh = 0x0000
bSynchAddress = 0x0000
Interface 0 Alt 11
bLength = 0x0009
bDescriptorType = 0x0004
bInterfaceNumber = 0x0000
bAlternateSetting = 0x000b
bNumEndpoints = 0x0003
bInterfaceClass = 0x0000
bInterfaceSubClass = 0x0000
bInterfaceProtocol = 0x0000
iInterface = 0x0000 <no string>
Endpoint 0
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0081 <IN>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 1
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0001 <OUT>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 2
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0082 <IN>
bmAttributes = 0x0001 <ISOCHRONOUS>
wMaxPacketSize = 0x0080
bInterval = 0x0001
bRefresh = 0x0000
bSynchAddress = 0x0000
Interface 0 Alt 12
bLength = 0x0009
bDescriptorType = 0x0004
bInterfaceNumber = 0x0000
bAlternateSetting = 0x000c
bNumEndpoints = 0x0003
bInterfaceClass = 0x0000
bInterfaceSubClass = 0x0000
bInterfaceProtocol = 0x0000
iInterface = 0x0000 <no string>
Endpoint 0
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0081 <IN>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 1
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0001 <OUT>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0020
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
Endpoint 2
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0082 <IN>
bmAttributes = 0x0001 <ISOCHRONOUS>
wMaxPacketSize = 0x0040
bInterval = 0x0001
bRefresh = 0x0000
bSynchAddress = 0x0000
Interface 1
bLength = 0x0009
bDescriptorType = 0x0004
bInterfaceNumber = 0x0001
bAlternateSetting = 0x0000
bNumEndpoints = 0x0001
bInterfaceClass = 0x0000
bInterfaceSubClass = 0x0000
bInterfaceProtocol = 0x0000
iInterface = 0x0000 <no string>
Endpoint 0
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0002 <OUT>
bmAttributes = 0x0002 <BULK>
wMaxPacketSize = 0x0008
bInterval = 0x0000
bRefresh = 0x0000
bSynchAddress = 0x0000
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Alternate setting 1 must be selected for interface 0 on the model that I received. Else the rest is identical.
2011-05-23 18:48 ` Hans Petter Selasky
@ 2011-05-23 19:06 ` Mauro Carvalho Chehab
2011-05-23 19:17 ` Hans Petter Selasky
0 siblings, 1 reply; 9+ messages in thread
From: Mauro Carvalho Chehab @ 2011-05-23 19:06 UTC (permalink / raw)
To: Hans Petter Selasky; +Cc: linux-media@vger.kernel.org
Em 23-05-2011 15:48, Hans Petter Selasky escreveu:
> On Monday 23 May 2011 20:14:45 Mauro Carvalho Chehab wrote:
>> Em 23-05-2011 11:37, Hans Petter Selasky escreveu:
>>
>> I don't have any ttusb device here, but I doubt that this would work.
>
> Hi,
>
> It is already tested and works fine.
This will work for you, but it will likely break for the others. Your patch
is assuming that returning an error if selecting alt 1 is enough to know that
alt 0 should be used.
> What I see is that interface 1 does not have an alternate setting like the
> driver code expects, while interface 0 does. So it is the opposite of what the
> driver expects. Maybe the manufacturer changed something. Endpoints are still
> the same.
That sometimes happen. Or maybe you just need a different size.
>
> Please find attached an USB descriptor dump from this device.
Int 0, endpoint 0:
Interface 0
bLength = 0x0009
bDescriptorType = 0x0004
bInterfaceNumber = 0x0000
bAlternateSetting = 0x0000
bNumEndpoints = 0x0003
bInterfaceClass = 0x0000
bInterfaceSubClass = 0x0000
bInterfaceProtocol = 0x0000
iInterface = 0x0000 <no string>
...
Endpoint 2
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0082 <IN>
bmAttributes = 0x0001 <ISOCHRONOUS>
wMaxPacketSize = 0x0000
bInterval = 0x0001
bRefresh = 0x0000
bSynchAddress = 0x0000
...
Interface 0 Alt 1
bLength = 0x0009
bDescriptorType = 0x0004
bInterfaceNumber = 0x0000
bAlternateSetting = 0x0001
bNumEndpoints = 0x0003
bInterfaceClass = 0x0000
bInterfaceSubClass = 0x0000
bInterfaceProtocol = 0x0000
iInterface = 0x0000 <no string>
...
Endpoint 2
bLength = 0x0007
bDescriptorType = 0x0005
bEndpointAddress = 0x0082 <IN>
bmAttributes = 0x0001 <ISOCHRONOUS>
wMaxPacketSize = 0x0390
bInterval = 0x0001
bRefresh = 0x0000
bSynchAddress = 0x0000
Hmm... assuming that the driver is using ISOC transfers, the difference between
alt 0 and alt 1 is that, on alt0, the mwMaxPacketSize is 0 (so, you can't use it
for isoc transfers), while, on alt 1, wMaxPacketSize is 0x390.
What the driver should be doing is to select an alt mode where the wMaxPacketSize is
big enough to handle the transfer.
Calculating what "big enough" is device-dependent, but, basically, a 480 Mbps
USB bus is capable of providing 800 isoc slots per interval. If the packets are bigger,
the max bandwidth is bigger.
You're able to see the amount of packets per interval by doing a cat /proc/bus/usb/devices:
T: Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=480 MxCh= 8
B: Alloc= 0/800 us ( 0%), #Int= 0, #Iso= 0
The "B:" line above shows the USB bandwidth usage.
>
>>
>> Alternates should be selected depending on the bandwidth needed. The right
>> way is to write some logic that will get the maximum packet size for each
>> mode, between the alternates that provide the type of transfer (Bulk or
>> ISOC) accepted by the driver.
>
> Right, but this driver doesn't do this. It only selects a working one.
>
> --HPS
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Alternate setting 1 must be selected for interface 0 on the model that I received. Else the rest is identical.
2011-05-23 19:06 ` Mauro Carvalho Chehab
@ 2011-05-23 19:17 ` Hans Petter Selasky
2011-05-23 19:47 ` Mauro Carvalho Chehab
0 siblings, 1 reply; 9+ messages in thread
From: Hans Petter Selasky @ 2011-05-23 19:17 UTC (permalink / raw)
To: Mauro Carvalho Chehab; +Cc: linux-media@vger.kernel.org
On Monday 23 May 2011 21:06:32 Mauro Carvalho Chehab wrote:
> Em 23-05-2011 15:48, Hans Petter Selasky escreveu:
> > On Monday 23 May 2011 20:14:45 Mauro Carvalho Chehab wrote:
> >> Em 23-05-2011 11:37, Hans Petter Selasky escreveu:
> >>
> >> I don't have any ttusb device here, but I doubt that this would work.
> >
> > Hi,
> >
> > It is already tested and works fine.
>
> This will work for you, but it will likely break for the others. Your patch
> is assuming that returning an error if selecting alt 1 is enough to know
> that alt 0 should be used.
>
> > What I see is that interface 1 does not have an alternate setting like
> > the driver code expects, while interface 0 does. So it is the opposite
> > of what the driver expects. Maybe the manufacturer changed something.
> > Endpoints are still the same.
>
> That sometimes happen. Or maybe you just need a different size.
>
> > Please find attached an USB descriptor dump from this device.
>
> Int 0, endpoint 0:
>
> Interface 0
> bLength = 0x0009
> bDescriptorType = 0x0004
> bInterfaceNumber = 0x0000
> bAlternateSetting = 0x0000
> bNumEndpoints = 0x0003
> bInterfaceClass = 0x0000
> bInterfaceSubClass = 0x0000
> bInterfaceProtocol = 0x0000
> iInterface = 0x0000 <no string>
>
> ...
>
> Endpoint 2
> bLength = 0x0007
> bDescriptorType = 0x0005
> bEndpointAddress = 0x0082 <IN>
> bmAttributes = 0x0001 <ISOCHRONOUS>
> wMaxPacketSize = 0x0000
> bInterval = 0x0001
> bRefresh = 0x0000
> bSynchAddress = 0x0000
>
> ...
>
> Interface 0 Alt 1
> bLength = 0x0009
> bDescriptorType = 0x0004
> bInterfaceNumber = 0x0000
> bAlternateSetting = 0x0001
> bNumEndpoints = 0x0003
> bInterfaceClass = 0x0000
> bInterfaceSubClass = 0x0000
> bInterfaceProtocol = 0x0000
> iInterface = 0x0000 <no string>
>
> ...
> Endpoint 2
> bLength = 0x0007
> bDescriptorType = 0x0005
> bEndpointAddress = 0x0082 <IN>
> bmAttributes = 0x0001 <ISOCHRONOUS>
> wMaxPacketSize = 0x0390
> bInterval = 0x0001
> bRefresh = 0x0000
> bSynchAddress = 0x0000
>
Hi,
> Hmm... assuming that the driver is using ISOC transfers, the difference
> between alt 0 and alt 1 is that, on alt0, the mwMaxPacketSize is 0 (so,
> you can't use it for isoc transfers), while, on alt 1, wMaxPacketSize is
> 0x390.
>
> What the driver should be doing is to select an alt mode where the
> wMaxPacketSize is big enough to handle the transfer.
I can write the code to do that. Summed up:
1) Search interface 0, for alternate settings that have an ISOC-IN and
wMaxPacket != 0. Select this alternate setting.
2) Search interface 1, for alternate settings that have an ISOC-IN and
wMaxPacket != 0. Select this alternate setting.
3) Done.
Do you think this will work better?
> Calculating what "big enough" is device-dependent, but, basically, a 480
> Mbps USB bus is capable of providing 800 isoc slots per interval. If the
> packets are bigger, the max bandwidth is bigger.
This is a FULL speed device, max 10MBit/second.
> You're able to see the amount of packets per interval by doing a cat
> /proc/bus/usb/devices:
>
> T: Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=480 MxCh= 8
> B: Alloc= 0/800 us ( 0%), #Int= 0, #Iso= 0
>
> The "B:" line above shows the USB bandwidth usage.
Do you need this information to proceed with the patch?
--HPS
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Alternate setting 1 must be selected for interface 0 on the model that I received. Else the rest is identical.
2011-05-23 19:17 ` Hans Petter Selasky
@ 2011-05-23 19:47 ` Mauro Carvalho Chehab
2011-05-23 19:52 ` Hans Petter Selasky
0 siblings, 1 reply; 9+ messages in thread
From: Mauro Carvalho Chehab @ 2011-05-23 19:47 UTC (permalink / raw)
To: Hans Petter Selasky; +Cc: linux-media@vger.kernel.org
Em 23-05-2011 16:17, Hans Petter Selasky escreveu:
> On Monday 23 May 2011 21:06:32 Mauro Carvalho Chehab wrote:
>> Em 23-05-2011 15:48, Hans Petter Selasky escreveu:
>>> On Monday 23 May 2011 20:14:45 Mauro Carvalho Chehab wrote:
>>>> Em 23-05-2011 11:37, Hans Petter Selasky escreveu:
>>>>
>>>> I don't have any ttusb device here, but I doubt that this would work.
>>>
>>> Hi,
>>>
>>> It is already tested and works fine.
>>
>> This will work for you, but it will likely break for the others. Your patch
>> is assuming that returning an error if selecting alt 1 is enough to know
>> that alt 0 should be used.
>>
>>> What I see is that interface 1 does not have an alternate setting like
>>> the driver code expects, while interface 0 does. So it is the opposite
>>> of what the driver expects. Maybe the manufacturer changed something.
>>> Endpoints are still the same.
>>
>> That sometimes happen. Or maybe you just need a different size.
>>
>>> Please find attached an USB descriptor dump from this device.
>>
>> Int 0, endpoint 0:
>>
>> Interface 0
>> bLength = 0x0009
>> bDescriptorType = 0x0004
>> bInterfaceNumber = 0x0000
>> bAlternateSetting = 0x0000
>> bNumEndpoints = 0x0003
>> bInterfaceClass = 0x0000
>> bInterfaceSubClass = 0x0000
>> bInterfaceProtocol = 0x0000
>> iInterface = 0x0000 <no string>
>>
>> ...
>>
>> Endpoint 2
>> bLength = 0x0007
>> bDescriptorType = 0x0005
>> bEndpointAddress = 0x0082 <IN>
>> bmAttributes = 0x0001 <ISOCHRONOUS>
>> wMaxPacketSize = 0x0000
>> bInterval = 0x0001
>> bRefresh = 0x0000
>> bSynchAddress = 0x0000
>>
>> ...
>>
>> Interface 0 Alt 1
>> bLength = 0x0009
>> bDescriptorType = 0x0004
>> bInterfaceNumber = 0x0000
>> bAlternateSetting = 0x0001
>> bNumEndpoints = 0x0003
>> bInterfaceClass = 0x0000
>> bInterfaceSubClass = 0x0000
>> bInterfaceProtocol = 0x0000
>> iInterface = 0x0000 <no string>
>>
>> ...
>> Endpoint 2
>> bLength = 0x0007
>> bDescriptorType = 0x0005
>> bEndpointAddress = 0x0082 <IN>
>> bmAttributes = 0x0001 <ISOCHRONOUS>
>> wMaxPacketSize = 0x0390
>> bInterval = 0x0001
>> bRefresh = 0x0000
>> bSynchAddress = 0x0000
>>
>
> Hi,
>
>> Hmm... assuming that the driver is using ISOC transfers, the difference
>> between alt 0 and alt 1 is that, on alt0, the mwMaxPacketSize is 0 (so,
>> you can't use it for isoc transfers), while, on alt 1, wMaxPacketSize is
>> 0x390.
>>
>> What the driver should be doing is to select an alt mode where the
>> wMaxPacketSize is big enough to handle the transfer.
>
> I can write the code to do that. Summed up:
>
> 1) Search interface 0, for alternate settings that have an ISOC-IN and
> wMaxPacket != 0. Select this alternate setting.
>
> 2) Search interface 1, for alternate settings that have an ISOC-IN and
> wMaxPacket != 0. Select this alternate setting.
>
> 3) Done.
>
> Do you think this will work better?
>
>> Calculating what "big enough" is device-dependent, but, basically, a 480
>> Mbps USB bus is capable of providing 800 isoc slots per interval. If the
>> packets are bigger, the max bandwidth is bigger.
>
> This is a FULL speed device, max 10MBit/second.
Hmm... USB 1.1 devices are even more limited on the amount of used bandwidth.
The above procedure is better than the one you've proposed, but yet you may
not be able to receive channels with higher bandwidths.
The usb "max" limit is lower than the maximum bandwidth. I think that full
speed provides 900 isoc slots per interval, but the interval for usb 1.1 is
higher (1s, while the interval for usb 2.0 is 125 us), but you need to double
check such constraints at the USB 1.1 and 2.0 specs, as I may be wrong on that,
as I read it a long time ago ;)
The proper way would be to have a function that would dynamically select
the alternate depending on the channel bandwidth and on the stream needs.
Someone might of course just write a code that selects the highest wMaxPacket,
but this would cause some troubles if another device is connected to the
USB 1.1 bus.
>
>> You're able to see the amount of packets per interval by doing a cat
>> /proc/bus/usb/devices:
>>
>> T: Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=480 MxCh= 8
>> B: Alloc= 0/800 us ( 0%), #Int= 0, #Iso= 0
>>
>> The "B:" line above shows the USB bandwidth usage.
>
> Do you need this information to proceed with the patch?
>
> --HPS
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Alternate setting 1 must be selected for interface 0 on the model that I received. Else the rest is identical.
2011-05-23 19:47 ` Mauro Carvalho Chehab
@ 2011-05-23 19:52 ` Hans Petter Selasky
2011-05-23 20:04 ` Mauro Carvalho Chehab
0 siblings, 1 reply; 9+ messages in thread
From: Hans Petter Selasky @ 2011-05-23 19:52 UTC (permalink / raw)
To: Mauro Carvalho Chehab; +Cc: linux-media@vger.kernel.org
On Monday 23 May 2011 21:47:57 Mauro Carvalho Chehab wrote:
> Em 23-05-2011 16:17, Hans Petter Selasky escreveu:
> > On Monday 23 May 2011 21:06:32 Mauro Carvalho Chehab wrote:
> >> Em 23-05-2011 15:48, Hans Petter Selasky escreveu:
> >>> On Monday 23 May 2011 20:14:45 Mauro Carvalho Chehab wrote:
> >>>> Em 23-05-2011 11:37, Hans Petter Selasky escreveu:
> >>>>
> >>>> I don't have any ttusb device here, but I doubt that this would work.
> >>>
> >>> Hi,
> >>>
> >>> It is already tested and works fine.
> >>
> >> This will work for you, but it will likely break for the others. Your
> >> patch is assuming that returning an error if selecting alt 1 is enough
> >> to know that alt 0 should be used.
> >>
> >>> What I see is that interface 1 does not have an alternate setting like
> >>> the driver code expects, while interface 0 does. So it is the opposite
> >>> of what the driver expects. Maybe the manufacturer changed something.
> >>> Endpoints are still the same.
> >>
> >> That sometimes happen. Or maybe you just need a different size.
> >>
> >>> Please find attached an USB descriptor dump from this device.
> >>
> >> Int 0, endpoint 0:
> >> Interface 0
> >>
> >> bLength = 0x0009
> >> bDescriptorType = 0x0004
> >> bInterfaceNumber = 0x0000
> >> bAlternateSetting = 0x0000
> >> bNumEndpoints = 0x0003
> >> bInterfaceClass = 0x0000
> >> bInterfaceSubClass = 0x0000
> >> bInterfaceProtocol = 0x0000
> >> iInterface = 0x0000 <no string>
> >>
> >> ...
> >>
> >> Endpoint 2
> >>
> >> bLength = 0x0007
> >> bDescriptorType = 0x0005
> >> bEndpointAddress = 0x0082 <IN>
> >> bmAttributes = 0x0001 <ISOCHRONOUS>
> >> wMaxPacketSize = 0x0000
> >> bInterval = 0x0001
> >> bRefresh = 0x0000
> >> bSynchAddress = 0x0000
> >>
> >> ...
> >>
> >> Interface 0 Alt 1
> >>
> >> bLength = 0x0009
> >> bDescriptorType = 0x0004
> >> bInterfaceNumber = 0x0000
> >> bAlternateSetting = 0x0001
> >> bNumEndpoints = 0x0003
> >> bInterfaceClass = 0x0000
> >> bInterfaceSubClass = 0x0000
> >> bInterfaceProtocol = 0x0000
> >> iInterface = 0x0000 <no string>
> >>
> >> ...
> >>
> >> Endpoint 2
> >>
> >> bLength = 0x0007
> >> bDescriptorType = 0x0005
> >> bEndpointAddress = 0x0082 <IN>
> >> bmAttributes = 0x0001 <ISOCHRONOUS>
> >> wMaxPacketSize = 0x0390
> >> bInterval = 0x0001
> >> bRefresh = 0x0000
> >> bSynchAddress = 0x0000
> >
> > Hi,
> >
> >> Hmm... assuming that the driver is using ISOC transfers, the difference
> >> between alt 0 and alt 1 is that, on alt0, the mwMaxPacketSize is 0 (so,
> >> you can't use it for isoc transfers), while, on alt 1, wMaxPacketSize is
> >> 0x390.
> >>
> >> What the driver should be doing is to select an alt mode where the
> >> wMaxPacketSize is big enough to handle the transfer.
> >
> > I can write the code to do that. Summed up:
> >
> > 1) Search interface 0, for alternate settings that have an ISOC-IN and
> > wMaxPacket != 0. Select this alternate setting.
> >
> > 2) Search interface 1, for alternate settings that have an ISOC-IN and
> > wMaxPacket != 0. Select this alternate setting.
> >
> > 3) Done.
> >
> > Do you think this will work better?
> >
> >> Calculating what "big enough" is device-dependent, but, basically, a
> >> 480 Mbps USB bus is capable of providing 800 isoc slots per interval.
> >> If the packets are bigger, the max bandwidth is bigger.
> >
> > This is a FULL speed device, max 10MBit/second.
>
> Hmm... USB 1.1 devices are even more limited on the amount of used
> bandwidth. The above procedure is better than the one you've proposed, but
> yet you may not be able to receive channels with higher bandwidths.
>
> The usb "max" limit is lower than the maximum bandwidth. I think that full
> speed provides 900 isoc slots per interval, but the interval for usb 1.1 is
> higher (1s, while the interval for usb 2.0 is 125 us), but you need to
> double check such constraints at the USB 1.1 and 2.0 specs, as I may be
> wrong on that, as I read it a long time ago ;)
Hi,
There are 1000 frames per second when using Full Speed USB. I know the device
cannot receive all streams, but it is very well suited for DVB radio.
--HPS
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Alternate setting 1 must be selected for interface 0 on the model that I received. Else the rest is identical.
2011-05-23 19:52 ` Hans Petter Selasky
@ 2011-05-23 20:04 ` Mauro Carvalho Chehab
2011-05-23 20:07 ` Hans Petter Selasky
0 siblings, 1 reply; 9+ messages in thread
From: Mauro Carvalho Chehab @ 2011-05-23 20:04 UTC (permalink / raw)
To: Hans Petter Selasky; +Cc: linux-media@vger.kernel.org
Em 23-05-2011 16:52, Hans Petter Selasky escreveu:
> On Monday 23 May 2011 21:47:57 Mauro Carvalho Chehab wrote:
>> Em 23-05-2011 16:17, Hans Petter Selasky escreveu:
>>> On Monday 23 May 2011 21:06:32 Mauro Carvalho Chehab wrote:
>>>> Em 23-05-2011 15:48, Hans Petter Selasky escreveu:
>>>>> On Monday 23 May 2011 20:14:45 Mauro Carvalho Chehab wrote:
>>>>>> Em 23-05-2011 11:37, Hans Petter Selasky escreveu:
>>>>>>
>>>>>> I don't have any ttusb device here, but I doubt that this would work.
>>>>>
>>>>> Hi,
>>>>>
>>>>> It is already tested and works fine.
>>>>
>>>> This will work for you, but it will likely break for the others. Your
>>>> patch is assuming that returning an error if selecting alt 1 is enough
>>>> to know that alt 0 should be used.
>>>>
>>>>> What I see is that interface 1 does not have an alternate setting like
>>>>> the driver code expects, while interface 0 does. So it is the opposite
>>>>> of what the driver expects. Maybe the manufacturer changed something.
>>>>> Endpoints are still the same.
>>>>
>>>> That sometimes happen. Or maybe you just need a different size.
>>>>
>>>>> Please find attached an USB descriptor dump from this device.
>>>>
>>>> Int 0, endpoint 0:
>>>> Interface 0
>>>>
>>>> bLength = 0x0009
>>>> bDescriptorType = 0x0004
>>>> bInterfaceNumber = 0x0000
>>>> bAlternateSetting = 0x0000
>>>> bNumEndpoints = 0x0003
>>>> bInterfaceClass = 0x0000
>>>> bInterfaceSubClass = 0x0000
>>>> bInterfaceProtocol = 0x0000
>>>> iInterface = 0x0000 <no string>
>>>>
>>>> ...
>>>>
>>>> Endpoint 2
>>>>
>>>> bLength = 0x0007
>>>> bDescriptorType = 0x0005
>>>> bEndpointAddress = 0x0082 <IN>
>>>> bmAttributes = 0x0001 <ISOCHRONOUS>
>>>> wMaxPacketSize = 0x0000
>>>> bInterval = 0x0001
>>>> bRefresh = 0x0000
>>>> bSynchAddress = 0x0000
>>>>
>>>> ...
>>>>
>>>> Interface 0 Alt 1
>>>>
>>>> bLength = 0x0009
>>>> bDescriptorType = 0x0004
>>>> bInterfaceNumber = 0x0000
>>>> bAlternateSetting = 0x0001
>>>> bNumEndpoints = 0x0003
>>>> bInterfaceClass = 0x0000
>>>> bInterfaceSubClass = 0x0000
>>>> bInterfaceProtocol = 0x0000
>>>> iInterface = 0x0000 <no string>
>>>>
>>>> ...
>>>>
>>>> Endpoint 2
>>>>
>>>> bLength = 0x0007
>>>> bDescriptorType = 0x0005
>>>> bEndpointAddress = 0x0082 <IN>
>>>> bmAttributes = 0x0001 <ISOCHRONOUS>
>>>> wMaxPacketSize = 0x0390
>>>> bInterval = 0x0001
>>>> bRefresh = 0x0000
>>>> bSynchAddress = 0x0000
>>>
>>> Hi,
>>>
>>>> Hmm... assuming that the driver is using ISOC transfers, the difference
>>>> between alt 0 and alt 1 is that, on alt0, the mwMaxPacketSize is 0 (so,
>>>> you can't use it for isoc transfers), while, on alt 1, wMaxPacketSize is
>>>> 0x390.
>>>>
>>>> What the driver should be doing is to select an alt mode where the
>>>> wMaxPacketSize is big enough to handle the transfer.
>>>
>>> I can write the code to do that. Summed up:
>>>
>>> 1) Search interface 0, for alternate settings that have an ISOC-IN and
>>> wMaxPacket != 0. Select this alternate setting.
>>>
>>> 2) Search interface 1, for alternate settings that have an ISOC-IN and
>>> wMaxPacket != 0. Select this alternate setting.
>>>
>>> 3) Done.
>>>
>>> Do you think this will work better?
>>>
>>>> Calculating what "big enough" is device-dependent, but, basically, a
>>>> 480 Mbps USB bus is capable of providing 800 isoc slots per interval.
>>>> If the packets are bigger, the max bandwidth is bigger.
>>>
>>> This is a FULL speed device, max 10MBit/second.
>>
>> Hmm... USB 1.1 devices are even more limited on the amount of used
>> bandwidth. The above procedure is better than the one you've proposed, but
>> yet you may not be able to receive channels with higher bandwidths.
>>
>> The usb "max" limit is lower than the maximum bandwidth. I think that full
>> speed provides 900 isoc slots per interval, but the interval for usb 1.1 is
>> higher (1s, while the interval for usb 2.0 is 125 us), but you need to
>> double check such constraints at the USB 1.1 and 2.0 specs, as I may be
>> wrong on that, as I read it a long time ago ;)
>
> Hi,
>
> There are 1000 frames per second when using Full Speed USB.
No, it is 900. See [1]:
[1] http://www.google.com.br/url?sa=t&source=web&cd=1&ved=0CBgQFjAA&url=http%3A%2F%2Fmprolab.teipir.gr%2Fvivlio80X86%2Fusb11.pdf&ei=DrzaTfD5HqW90AHY-Jn8Aw&usg=AFQjCNHZW7ogFrjqoim1lTduQTHTDJoAUg
"5.6.4 Isochronous Transfer Bus Access Constraints
Isochronous transfers can be used only by full-speed devices.
The USB requires that no more than 90% of any frame be allocated for periodic (isochronous and
interrupt) transfers."
90% of 1000 frames is 900 frames/s. That's the maximum limit for ISOC transfers.
> I know the device
> cannot receive all streams, but it is very well suited for DVB radio.
Yeah, for DVB radio, that's ok, but the driver should be ok also for other
usages. Of course, streams with > 9Mbps won't fit on it, but if the driver
is not selecting the maximum alternate, the bandwidth limit will be even
smaller than that.
Mauro.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] Alternate setting 1 must be selected for interface 0 on the model that I received. Else the rest is identical.
2011-05-23 20:04 ` Mauro Carvalho Chehab
@ 2011-05-23 20:07 ` Hans Petter Selasky
0 siblings, 0 replies; 9+ messages in thread
From: Hans Petter Selasky @ 2011-05-23 20:07 UTC (permalink / raw)
To: Mauro Carvalho Chehab; +Cc: linux-media@vger.kernel.org
On Monday 23 May 2011 22:04:07 Mauro Carvalho Chehab wrote:
> Em 23-05-2011 16:52, Hans Petter Selasky escreveu:
> > On Monday 23 May 2011 21:47:57 Mauro Carvalho Chehab wrote:
> >> Em 23-05-2011 16:17, Hans Petter Selasky escreveu:
> >>> On Monday 23 May 2011 21:06:32 Mauro Carvalho Chehab wrote:
> >>>> Em 23-05-2011 15:48, Hans Petter Selasky escreveu:
> >>>>> On Monday 23 May 2011 20:14:45 Mauro Carvalho Chehab wrote:
> >>>>>> Em 23-05-2011 11:37, Hans Petter Selasky escreveu:
> >>>>>>
> >>>>>> I don't have any ttusb device here, but I doubt that this would
> >>>>>> work.
> >>>>>
> >>>>> Hi,
> >>>>>
> >>>>> It is already tested and works fine.
> >>>>
> >>>> This will work for you, but it will likely break for the others. Your
> >>>> patch is assuming that returning an error if selecting alt 1 is enough
> >>>> to know that alt 0 should be used.
> >>>>
> >>>>> What I see is that interface 1 does not have an alternate setting
> >>>>> like the driver code expects, while interface 0 does. So it is the
> >>>>> opposite of what the driver expects. Maybe the manufacturer changed
> >>>>> something. Endpoints are still the same.
> >>>>
> >>>> That sometimes happen. Or maybe you just need a different size.
> >>>>
> >>>>> Please find attached an USB descriptor dump from this device.
> >>>>
> >>>> Int 0, endpoint 0:
> >>>> Interface 0
> >>>>
> >>>> bLength = 0x0009
> >>>> bDescriptorType = 0x0004
> >>>> bInterfaceNumber = 0x0000
> >>>> bAlternateSetting = 0x0000
> >>>> bNumEndpoints = 0x0003
> >>>> bInterfaceClass = 0x0000
> >>>> bInterfaceSubClass = 0x0000
> >>>> bInterfaceProtocol = 0x0000
> >>>> iInterface = 0x0000 <no string>
> >>>>
> >>>> ...
> >>>>
> >>>> Endpoint 2
> >>>>
> >>>> bLength = 0x0007
> >>>> bDescriptorType = 0x0005
> >>>> bEndpointAddress = 0x0082 <IN>
> >>>> bmAttributes = 0x0001 <ISOCHRONOUS>
> >>>> wMaxPacketSize = 0x0000
> >>>> bInterval = 0x0001
> >>>> bRefresh = 0x0000
> >>>> bSynchAddress = 0x0000
> >>>>
> >>>> ...
> >>>>
> >>>> Interface 0 Alt 1
> >>>>
> >>>> bLength = 0x0009
> >>>> bDescriptorType = 0x0004
> >>>> bInterfaceNumber = 0x0000
> >>>> bAlternateSetting = 0x0001
> >>>> bNumEndpoints = 0x0003
> >>>> bInterfaceClass = 0x0000
> >>>> bInterfaceSubClass = 0x0000
> >>>> bInterfaceProtocol = 0x0000
> >>>> iInterface = 0x0000 <no string>
> >>>>
> >>>> ...
> >>>>
> >>>> Endpoint 2
> >>>>
> >>>> bLength = 0x0007
> >>>> bDescriptorType = 0x0005
> >>>> bEndpointAddress = 0x0082 <IN>
> >>>> bmAttributes = 0x0001 <ISOCHRONOUS>
> >>>> wMaxPacketSize = 0x0390
> >>>> bInterval = 0x0001
> >>>> bRefresh = 0x0000
> >>>> bSynchAddress = 0x0000
> >>>
> >>> Hi,
> >>>
> >>>> Hmm... assuming that the driver is using ISOC transfers, the
> >>>> difference between alt 0 and alt 1 is that, on alt0, the
> >>>> mwMaxPacketSize is 0 (so, you can't use it for isoc transfers),
> >>>> while, on alt 1, wMaxPacketSize is 0x390.
> >>>>
> >>>> What the driver should be doing is to select an alt mode where the
> >>>> wMaxPacketSize is big enough to handle the transfer.
> >>>
> >>> I can write the code to do that. Summed up:
> >>>
> >>> 1) Search interface 0, for alternate settings that have an ISOC-IN and
> >>> wMaxPacket != 0. Select this alternate setting.
> >>>
> >>> 2) Search interface 1, for alternate settings that have an ISOC-IN and
> >>> wMaxPacket != 0. Select this alternate setting.
> >>>
> >>> 3) Done.
> >>>
> >>> Do you think this will work better?
> >>>
> >>>> Calculating what "big enough" is device-dependent, but, basically, a
> >>>> 480 Mbps USB bus is capable of providing 800 isoc slots per interval.
> >>>> If the packets are bigger, the max bandwidth is bigger.
> >>>
> >>> This is a FULL speed device, max 10MBit/second.
> >>
> >> Hmm... USB 1.1 devices are even more limited on the amount of used
> >> bandwidth. The above procedure is better than the one you've proposed,
> >> but yet you may not be able to receive channels with higher bandwidths.
> >>
> >> The usb "max" limit is lower than the maximum bandwidth. I think that
> >> full speed provides 900 isoc slots per interval, but the interval for
> >> usb 1.1 is higher (1s, while the interval for usb 2.0 is 125 us), but
> >> you need to double check such constraints at the USB 1.1 and 2.0 specs,
> >> as I may be wrong on that, as I read it a long time ago ;)
> >
> > Hi,
> >
> > There are 1000 frames per second when using Full Speed USB.
>
> No, it is 900. See [1]:
>
> [1]
> http://www.google.com.br/url?sa=t&source=web&cd=1&ved=0CBgQFjAA&url=http%3
> A%2F%2Fmprolab.teipir.gr%2Fvivlio80X86%2Fusb11.pdf&ei=DrzaTfD5HqW90AHY-Jn8A
> w&usg=AFQjCNHZW7ogFrjqoim1lTduQTHTDJoAUg
>
> "5.6.4 Isochronous Transfer Bus Access Constraints
> Isochronous transfers can be used only by full-speed devices.
> The USB requires that no more than 90% of any frame be allocated for
> periodic (isochronous and interrupt) transfers."
>
> 90% of 1000 frames is 900 frames/s. That's the maximum limit for ISOC
> transfers.
Hi,
FULL speed USB has 1000 frames per second which is constant. During each frame
that last 1ms you can send max 1200 bytes approximately simplex. You are
allowed to use up to 90% of 1200 bytes, which is 1080 bytes which is just
above the maximum of 1023 bytes for isochronous transfers.
Hope you see now!
--HPS
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2011-05-23 20:09 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-05-23 14:37 [PATCH] Alternate setting 1 must be selected for interface 0 on the model that I received. Else the rest is identical Hans Petter Selasky
2011-05-23 18:14 ` Mauro Carvalho Chehab
2011-05-23 18:48 ` Hans Petter Selasky
2011-05-23 19:06 ` Mauro Carvalho Chehab
2011-05-23 19:17 ` Hans Petter Selasky
2011-05-23 19:47 ` Mauro Carvalho Chehab
2011-05-23 19:52 ` Hans Petter Selasky
2011-05-23 20:04 ` Mauro Carvalho Chehab
2011-05-23 20:07 ` Hans Petter Selasky
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