DM355 USB Hub Support

mmm, according to the driver data manual, we do support USB HUBs.  Are you operating EVM in USB Host mode?  Does the HUB you are plugging in have its own power supply?  I do not belive the USB port is capable of powering a USB Hub.  Also, what Rev DM355 EVM board are you using?  I believe there was a USB soldering issue on a small batch of Rev E boards (unlikely you got one, but worth mntioning); if you got one of these boards, USB should not work for any device...

I'm using a small unpowered hub. I checked the voltage levels at the EVM USB connector before and after hub insertion and they are fine at 5V so it doesn't look like the EVM PSU is being loaded up. The hub works in my desktop Linux PC. The EVM successfully sees a USB memory stick if the stick is plugged directly into the EVM without a hub.

The kernel menuconfig for USB is:

Linux Kernel v2.6.10_mvl401 Configuration
│ │           <*> Support for Host-side USB
│ │           [ ]   USB verbose debug messages
│ │           ---   Miscellaneous USB options
│ │           [*]   USB device filesystem  
│ │           [ ]   Enforce USB bandwidth allocation (EXPERIMENTAL)
│ │           [ ]   Dynamic USB minor allocation (EXPERIMENTAL)
│ │           [ ]   USB suspend/resume (EXPERIMENTAL) 
│ │           --- USB Host Controller Drivers 
│ │           < > SL811HS HCD support
│ │           <*> Inventra USB Highspeed Dual Role Controller Support  
│ │           ---   DaVinci 644x USB support 
│ │                 Driver Mode (USB Host)  ---> 
│ │           [ ] Reserve ISO EndPoints   
│ │           [ ] Disable DMA (always use PIO) 
│ │           (0) Logging Level (0 - none / 3 - annoying / ... ) 
│ │           --- USB Device Class drivers  
│ │           < > USB Audio support    
│ │           < > USB Bluetooth TTY support
│ │           < > USB MIDI support   
│ │           < > USB Modem (CDC ACM) support 
│ │           < > USB Printer support    
│ │           <*> USB Mass Storage support   
│ │           [ ]   USB Mass Storage verbose debug   
│ │           [ ]   USB Mass Storage Write-Protected Media Detection (EXPERIMENTAL) 
│ │           [ ]   Datafab Compact Flash Reader support (EXPERIMENTAL) 
│ │           [ ]   Freecom USB/ATAPI Bridge support  
│ │           [ ]   Microtech/ZiO! CompactFlash/SmartMedia support  
│ │           [ ]   HP CD-Writer 82xx support (EXPERIMENTAL) 
│ │           [ ]   SanDisk SDDR-09 (and other SmartMedia) support (EXPERIMENTAL) 
│ │           [ ]   SanDisk SDDR-55 SmartMedia support (EXPERIMENTAL) 
│ │           [ ]   Lexar Jumpshot Compact Flash Reader (EXPERIMENTAL) 
│ │           [ ]   Support OneTouch Button on Maxtor Hard Drives (EXPERIMENTAL) 
│ │           --- USB Input Devices  
│ │           < > USB Human Interface Device (full HID) support  
│ │                 USB HID Boot Protocol drivers  --->  
│ │           < > Aiptek 6000U/8000U tablet support 
│ │           < > Wacom Intuos/Graphire tablet support   
│ │           < > KB Gear JamStudio tablet support  
│ │           < > Griffin PowerMate and Contour Jog support  
│ │           < > MicroTouch USB Touchscreen Driver  
│ │           < > eGalax TouchKit USB Touchscreen Driver   
│ │           < > X-Box gamepad support  
│ │           < > ATI / X10 USB RF remote control  
│ │           < > ATI / X10 USB RF remote control  
│ │           --- USB Imaging devices 
│ │           < > USB Mustek MDC800 Digital Camera support (EXPERIMENTAL) 
│ │           < > Microtek X6USB scanner support  
│ │           < > HP53xx USB scanner support   
│ │           --- USB Multimedia devices  
│ │           < > DABUSB driver  
│ │           < > USB 3com HomeConnect (aka vicam) support (EXPERIMENTAL) 
│ │           < > D-Link USB FM radio support (EXPERIMENTAL)  
│ │           < > USB IBM (Xirlink) C-it Camera support   
│ │           < > USB Konica Webcam support  

│ │           < > USB OV511 Camera support
│ │           < > USB SE401 Camera support
│ │           < > USB SN9C10x PC Camera Controller support  
│ │           < > USB STV680 (Pencam) Camera support  
│ │               USB Network Adapters  --->  
│ │           --- USB port drivers   
│ │               USB Serial Converter support  ---> 
│ │           --- USB Miscellaneous drivers         
│ │           < > EMI 6|2m USB Audio interface support
│ │           < > EMI 2|6 USB Audio interface support     
│ │           < > Texas Instruments Graph Link USB (aka SilverLink) cable support  
│ │           < > USB Auerswald ISDN support (EXPERIMENTAL)  
│ │           < > USB Diamond Rio500 support (EXPERIMENTAL)     
│ │           < > USB Lego Infrared Tower support (EXPERIMENTAL)   
│ │           < > USB LCD driver support   
│ │           < > USB LED driver support   
│ │           < > Cypress USB thermometer driver support  
│ │           < > USB PhidgetKit support   
│ │           < > USB PhidgetServo support   
│ │           < > USB testing driver (DEVELOPMENT) 
│ │           --- USB ATM/DSL drivers   
│ │               USB Gadget Support  --->  
│

I tried another 4 port hub from a different manufacturer, and it is detected and works fine. Plugged in 4 memory sticks into the hub and all can be mounted. Looks like the original hub was not recognised by the driver.

Are there particular hub chips that the Linux driver supports (or does not support)? We are particularly looking at using the Cypress CY7C65620 or the SMSC USB2512 in our product but will consider any full speed USB2 hub chip that is currently driver supported.

Steve,

DM355 supports all hubs (and hub chips) that are USB (1.1/2.0) compliant.  Default kernel usb config is sufficient to support hubs.

regards

swami