[PATCH] usb: dwc2: Set max xfer length to speed up R/W

Marek Vasut marex at denx.de
Wed Mar 24 12:39:18 CET 2021


On 3/24/21 7:11 AM, Cheng Lu wrote:
> Set transfer length to the maximum (65535 * 512) Bytes
> of SCSI READ(10) and WRITE(10) commands, while default
> transfer length is (20 * 512) Bytes

Please have a look at these four patches, increasing the transfer length 
would make some odd USB pen drives fail:

7d6fd7f0ba7 ("usb: storage: Limit transfer size to 120 kiB")
da3d1c499fb ("usb: storage: Only clear READY flag on error")
02b0e1a36c5 ("usb: ehci-hcd: Keep async schedule running")
31232de07ef ("usb: Keep async schedule running only across mass storage 
xfers")

Use the async schedule to avoid stopping the controller after every 
transfer and thus keep the throughput high, while avoiding very long 
transfers which might break odd USB pen drives.


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