Re: [PATCH 6/6] ibmveth: Remove use of bitfields

Brian King wrote:

Removes the use of bitfields from the ibmveth driver. This results
in slightly smaller object code.

Signed-off-by: Brian King <redacted>
---

 linux-2.6-bjking1/drivers/net/ibmveth.c |   90 ++++++++++++++++----------------
 linux-2.6-bjking1/drivers/net/ibmveth.h |   56 ++++++++-----------
 2 files changed, 68 insertions(+), 78 deletions(-)

strong ACK :)

Though I also encourage you to avoid #defines for named constants, in favor of

enum {
	IBMVETH_BUF_VALID	= (1U << 31),
	IBMVETH_BUF_TOGGLE	= (1U << 30),
	IBMVETH_BUF_NO_CSUM	= (1U << 25),
	IBMVETH_BUF_CSUM_GOOD	= (1U << 24),
	IBMVETH_BUF_LEN_MASK	= 0x00FFFFFF,
};

This illustrates:

1) The "1 << n" notation is FAR easier to read and compare with data sheets.  You're just adding to the trouble by requiring the reviewer's brain to convert hex numbers to bits, even if most engineers can do this in their sleep.

2) The named constants are available to the C compiler, which is more friendly to debuggers.  It also supplies type information to the C compiler.

3) Similar to #2, wading through C pre-processor output is much easier when the symbols don't disappear.

These are recommendations, not requirements, but I've found these techniques superior to cpp in many other drivers.

	Jeff