libpayload: usb mass storage detect empty media

There is currently a hard-coded 30 sec delay in the mass storage
driver while waiting for each device to become ready. However, mass
storage card readers that are empty return an error code on the
TEST UNIT READY command. A REQUEST SENSE command then needs to be
issued and interrogate the data to determine if no media is present.
If no media determination is found to be true the USB device is no
longer considered a candidate to be a disk.

This code does lead to the fact that the media card reader needs to be
populated at enumeration time. I suspect this is not an issue as it
appears the storage stack in libpayload can't handle removable media
coming online later.

Booted recovery and dev modes. Noted that removable mass storage
devices with no media were ignored without any boot delay.

Change-Id: Ida7a45614d97c6e6fbfc9bb099765aad4df550fd
Signed-off-by: Aaron Durbin <>
Reviewed-by: Duncan Laurie <>
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <>
1 file changed