On Fri 2021-02-05 20:12:01, Pali Rohár wrote:
> This patch fixes configuring FIFO for one-directional endpoints which have
> either RX or TX queue and therefore only one FIFO.
> 
> Size of FIFO buffer is 2^(idx+3) bytes and starting address is 2^(addr+3).
> Moreover first 64 bytes are reserved for EP0.
> 
> Without this patch if FIFO size specified by caller was zero then idx was
> incorrectly calculated (expr. ffs(0)-1) and size overflowed in fifosz
> register. This register uses has only 4 bits for FIFO size. Moreover
> specifying zero size is not possible.
> 
> This patch is fixing calculation of start address and buffer size to
> minimal value and ensure that it would not overlap with reserved EP0
> buffer.
> 
> This issue caused loose of packets on USB bus in both directions and
> basically usbtty was unusable.
> 
> Signed-off-by: Pali Rohár <p...@kernel.org>

1-5: Acked-by: Pavel Machek <pa...@ucw.cz>

-- 
http://www.livejournal.com/~pavelmachek

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