On 01/18/2015 09:12 PM, Ahmed S. Darwish wrote: > Hi! > > On Mon, Jan 12, 2015 at 02:53:02PM +0100, Olivier Sobrie wrote: >> Hello, >> >> On Sun, Jan 11, 2015 at 03:36:12PM -0500, Ahmed S. Darwish wrote: >>> From: Ahmed S. Darwish <[email protected]> >>> > > ... > >>> @@ -98,7 +128,13 @@ >>> #define CMD_START_CHIP_REPLY 27 >>> #define CMD_STOP_CHIP 28 >>> #define CMD_STOP_CHIP_REPLY 29 >>> -#define CMD_GET_CARD_INFO2 32 >>> +#define CMD_READ_CLOCK 30 >>> +#define CMD_READ_CLOCK_REPLY 31 >> >> These two defines are not used. >> > > They were added for completeness: the only gap in our continuous > sequence of command IDs from 12 to 39 ;-) No big deal, to be > removed in the next submission. > > ... > >>> + >>> +struct kvaser_msg_tx_acknowledge_header { >>> + u8 channel; >>> + u8 tid; >>> +}; >> >> Is this struct really needed? Can't you simply use >> leaf_msg_tx_acknowledge or usbcan_msg_tx_acknowledge >> structures to read the header. >> Same for kvaser_msg_rx_can_header. >> > > They're added to ensure type-safety throughout the code. Basically > they're the common part of a command that has different wire format > between the Leaf and the USBCan, but share a common header. Such > notation was only added when it was strictly necessary. > > For example, there are three functions where 'rx_can_header' is > referenced in the driver, and one function where 'tx_acknowledge_header' > is referenced. Without such header structure, I'll have to sprinkle > 3 to 4 extra blocks of: > > switch (dev->family) { > case KVASER_LEAF: > case KVASER_USBCAN: > } > > which would be _really_ ugly. The *_header notation ensures that, in > the body of each function, we're accessing the fields in a very safe > manner.
+1 Keep it as it is. Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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