Hi folks,
I'm using a PL2303-based USB ⇔ RS-232 adaptor (lsusb output appended).
However, when I try to send a break (using alt+F in minicom), it appears
that nothing at all happens.
If I enable the debug printing in the driver, I see the following:
pl2303_break_ctl - port 0
pl2303_break_ctl - turning break on
pl2303_break_ctl - error sending break = -32
pl2303_break_ctl - port 0
pl2303_break_ctl - turning break off
pl2303_break_ctl - error sending break = -32
-32 would appear to be EPIPE. With the debugging disabled these errors
get dropped on the floor, hence everything seems normal except that
nothing happens when I send a break. The adaptor seems to work
fine otherwise.
The machine is running Linux 3.1, but the same failure occurs on Linus'
master. I also tried 2.6.32 for good measure (no dice).
I have no idea where these errors are coming from or what they mean. Is
break supposed to work on this chip? If so, how can I track down the
issue?
# lsusb -v -d 067b:
Bus 004 Device 002: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x067b Prolific Technology, Inc.
idProduct 0x2303 PL2303 Serial Port
bcdDevice 3.00
iManufacturer 1 Prolific Technology Inc.
iProduct 2 USB 2.0 To COM Device
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 39
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 100mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 3
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 0
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x000a 1x 10 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Device Status: 0x0000
(Bus Powered)
Thanks,
--
Nick Bowler, Elliptic Technologies (http://www.elliptictech.com/)
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