mirror of
https://github.com/torvalds/linux.git
synced 2024-09-28 02:43:02 +00:00
c682b3a7fb
One bit wide bitfields need to declared unsigned to have the range 0 to 1, or they have the range -1 to 0. A few techniques to reduce the driver's size by about 1700 bytes on ia32, probably more on x86-64. Put the biggest fields first, less padding is necessary that way. Put fields with a limited range into a smaller type. For example VideoChannels will fit in 3 bits, and TunerType can use 8 bits. Vin_Reg1, Vin_Reg2, and Dvi_yuv define values for 8-bit registers, but they can't just go into an 8-bit field with no changes, since -1 was used as a flag to indicate a value was not present. So what we do is create a one-bit flag for each one to indicate if a value is or is not present. This only takes 9 bits and has the added advantage that when the register isn't overridden (Vin_Reg[12] never are) it doesn't need to appear in the structure definition since the default value for the flag will be zero. Signed-off-by: Trent Piepho <xyzzy@speakeasy.org> Acked-by: Thierry MERLE <thierry.merle@free.fr> Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org> |
||
|---|---|---|
| .. | ||
| common | ||
| dvb | ||
| radio | ||
| video | ||
| Kconfig | ||
| Makefile | ||