Re: [sfc:master 79/80] drivers/net/ethernet/sfc/mcdi.c:960:1: warning: 'efx_mcdi_print_fwver' uses dynamic stack allocation

On Sat, 2013-08-31 at 07:09 +0800, kbuild test robot wrote:

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/bwh/sfc-next master
head:   f7a6d2c4427790cc8695401576dc594fcce8fc80
commit: 8127d661e77f5ec410093bce411f540afa34593f [79/80] sfc: Add support for Solarflare SFC9100 family
config: make ARCH=s390 allmodconfig

All warnings:

   drivers/net/ethernet/sfc/mcdi.c: In function 'efx_mcdi_print_fwver':

quoted

quoted

drivers/net/ethernet/sfc/mcdi.c:960:1: warning: 'efx_mcdi_print_fwver' uses dynamic stack allocation [enabled by default]

[...]

What we actually do is:

	MCDI_DECLARE_BUF(outbuf,
			 max(MC_CMD_GET_VERSION_OUT_LEN,
			     MC_CMD_GET_CAPABILITIES_OUT_LEN));

The dimension of the outbuf array is constant, even though max() doesn't
expand to a compile-time constant expression.  It's odd that gcc would
complain about this specifically on s390 (or is it that you're using a
different compiler version there?).  I don't know whether anything can
or should be done about to fix the warning.

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.