[PATCH] USB speedtouch: speedtouch 330 support
Differences: speedtouch 330 vs the older speedtouch USB: Vendor and ProdID: no difference (!) Rev: 2.00 vs 0.00 SerialNumber: 0090D0xxxxxx, xxxxxx larger for 330 Interface 1, Alt 2: E: Ad=06(O) Atr=02(Bulk) MxPS=64 Ivl=0ms E: Ad=07(O) Atr=02(Bulk) MxPS=64 Ivl=0ms E: Ad=87(I) Atr=01(Isoc) MxPS=640 Ivl=1ms vs E: Ad=06(O) Atr=02(Bulk) MxPS=32 Ivl=0ms E: Ad=07(O) Atr=02(Bulk) MxPS=32 Ivl=0ms E: Ad=87(I) Atr=02(Bulk) MxPS=64 Ivl=0ms Interface 1, Alt 3: E: Ad=06(O) Atr=02(Bulk) MxPS=64 Ivl=0ms E: Ad=07(O) Atr=02(Bulk) MxPS=64 Ivl=0ms E: Ad=87(I) Atr=01(Isoc) MxPS=960 Ivl=1ms vs E: Ad=06(O) Atr=02(Bulk) MxPS=16 Ivl=0ms E: Ad=07(O) Atr=02(Bulk) MxPS=16 Ivl=0ms E: Ad=87(I) Atr=02(Bulk) MxPS=64 Ivl=0ms The current driver works with the speedtouch 330 as long as we use alternate setting 1 on interface 1 rather than alternate 2 as we do now. In fact it makes sense to use alternate 1 for the speedtouch USB as well: the difference is in the max packet size for the out bulk endpoint (0x07): 64 for Alt 1, 32 for Alt 2. Since we send only multiples of 53 bytes (ATM cell size), the potential lower latency for Alt 2 is not really exploitable (think about it!). My tests indicate no harm and perhaps a slight gain by using Alt 1. The manufacturer seems to think so too, since they chose to keep the Alt 1 setting and threw out Alt 2 when designing the 330. So just use Alt 1 for both modems.
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