media: stb0899_drv: Don't use dynamic static allocation
authorMauro Carvalho Chehab <m.chehab@samsung.com>
Sat, 2 Nov 2013 08:14:58 +0000 (05:14 -0300)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 4 Dec 2013 18:57:33 +0000 (10:57 -0800)
commit845b09830c162084301f65c947894389cd48e8b6
tree5cf0e4d0d5629fd19dd6dbba1c4c6e54ae277aa3
parent6d3ac5e79294ecf2c437de63e9a38d125b7c5922
media: stb0899_drv: Don't use dynamic static allocation

commit ba4746423488aafa435739c32bfe0758f3dd5d77 upstream.

Dynamic static allocation is evil, as Kernel stack is too low, and
compilation complains about it on some archs:
drivers/media/dvb-frontends/stb0899_drv.c:540:1: warning: 'stb0899_write_regs' uses dynamic stack allocation [enabled by default]
Instead, let's enforce a limit for the buffer. Considering that I2C
transfers are generally limited, and that devices used on USB has a
max data length of 64 bytes for the control URBs.
So, it seem safe to use 64 bytes as the hard limit for all those devices.
 On most cases, the limit is a way lower than that, but this limit
is small enough to not affect the Kernel stack, and it is a no brain
limit, as using smaller ones would require to either carefully each
driver or to take a look on each datasheet.

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/media/dvb-frontends/stb0899_drv.c