From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [Bluez-users] Once again: Socket CF card and Kernel 2.6 From: Marcel Holtmann To: BlueZ Mailing List In-Reply-To: <20050305141858.GA21208@adamis.de> References: <20050226031901.GL11723@adamis.de> <1109578431.17256.9.camel@pegasus> <20050228220209.GA8151@adamis.de> <1109665776.17256.122.camel@pegasus> <42294598.6010004@adamis.de> <1110021859.8058.111.camel@pegasus> <20050305141858.GA21208@adamis.de> Content-Type: text/plain Message-Id: <1110046671.18555.3.camel@pegasus> Mime-Version: 1.0 Sender: bluez-users-admin@lists.sourceforge.net Errors-To: bluez-users-admin@lists.sourceforge.net Reply-To: bluez-users@lists.sourceforge.net List-Unsubscribe: , List-Id: BlueZ users List-Post: List-Help: List-Subscribe: , List-Archive: Date: Sat, 05 Mar 2005 19:17:50 +0100 Hi Mathias, > > > I just got it working by doing a little change in the serial driver > > > (8250.c). I tested it with 2.6.11 but I think it could work for any 2.6 > > > kernel. > > > > please provide a patch for your change. > > So - after some cleaning - here it is. A short description: > > The BlueZ driver requests a baud rate > of 230400 which is uartclk/8 (serial_cs sets uartclk=1843200). However > serial8250_set_termios() refuses to program a baud rate larger than > uartclk/16 which should be ok for most UARTs. I looked into the 2.4 > driver and found some code that changes the internal prescaler to values > between 1:16 and 1:4 to support baud rates up to uartclk/4 respectively > (this is done for 16C950 UARTs only). The datasheet of oxford's oxcf950 > chip confirms this feature. > > Apply the patch to the file drivers/serial/8250.c > > Please let me know if there are problems or if it does work. I only have the old Socket cards (dtl1_cs driver) at hand and so I can't test it, but my Xircom card is still not working. > > > One thing I discovered while debugging this: the hci_uart driver > > > seems to initialize the actual UART with only 230400 baud. Is this > > > really the case or are those UARTs clocked at nonstandard (higher) > > > frequencies so that this setting does result in a higher real baud rate? > > > > The hci_uart is only a line discipline. Every initialization and baud > > rate settings are done with hciattach. > > ok so it's hciattach that sets the baudrate - but that wasn't the point > (or I misunderstood your answer?): I wonder if the bluetooth module is > really accessed at only 230400 baud (that's the rate which is given to > the 8250 driver) which seems a little bit slow thinking of bluetooths > >700kbaud maximum rate... For the Socket card the baud rate is 230400 and yes, this is to slow for the full bandwith of a piconet. However I never did any bandwith test with this card, but actually there are cards out there where the UART limits the total possible bandwidth. Regards Marcel ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ Bluez-users mailing list Bluez-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bluez-users