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| author | Tomasz Moń <desowin@gmail.com> | 2021-06-12 13:12:44 +0200 |
|---|---|---|
| committer | Tomasz Moń <desowin@gmail.com> | 2021-06-12 13:54:54 +0000 |
| commit | 663d846cf3867a6aab40b981b4755a1f62a64dcd (patch) | |
| tree | d9287ff97edf75865db5b5b9806cf10910806772 /firmware/export/usb_ch9.h | |
| parent | a90ef8195b13aada83da4e1773b5a14c20b33d0b (diff) | |
| download | rockbox-663d846cf3867a6aab40b981b4755a1f62a64dcd.tar.gz rockbox-663d846cf3867a6aab40b981b4755a1f62a64dcd.zip | |
Sansa Connect: Disable endpoint double buffering
Disabling double buffering results in expected CPPI TX behaviour. With
the double buffering enabled, sending single ZLP resulted in two ZLPs
being available. The two ZLPs is problematic because this causes Windows
to reset USB device after failed SCSI command.
The problematic sequence on Windows 10 was as follows:
* Host sends SCSI Mode Sense(6) Informational Exceptions Control(0x1C)
* Device sends ZLP
* Device sends command failed response
With endpoint double buffering enabled the ZLP was read twice by host.
As host was expecting command response on the second read (and got ZLP
instead), host attempts recovery by resetting USB device and retrying.
Change-Id: I64e95998f429ffb7b14143d956b1f29d20218d14
Diffstat (limited to 'firmware/export/usb_ch9.h')
0 files changed, 0 insertions, 0 deletions