media: dvb-frontends: Don't use dynamic static allocation
authorMauro Carvalho Chehab <m.chehab@samsung.com>
Sat, 2 Nov 2013 08:11:47 +0000 (05:11 -0300)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 4 Dec 2013 19:06:35 +0000 (11:06 -0800)
commit5e3c7ff0b050a7c9dd7319f4ca7cfebd3903d013
tree4c62112e2fb6a1810b8f6a5a3acee894cea4f87a
parenta385eab2d1f958759f9c23923b7749b0505285f6
media: dvb-frontends: Don't use dynamic static allocation

commit 37ebaf6891ee81687bb558e8375c0712d8264ed8 upstream.

Dynamic static allocation is evil, as Kernel stack is too low, and
compilation complains about it on some archs:
drivers/media/dvb-frontends/af9013.c:77:1: warning: 'af9013_wr_regs_i2c' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/af9033.c:188:1: warning: 'af9033_wr_reg_val_tab' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/af9033.c:68:1: warning: 'af9033_wr_regs' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/bcm3510.c:230:1: warning: 'bcm3510_do_hab_cmd' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/cxd2820r_core.c:84:1: warning: 'cxd2820r_rd_regs_i2c.isra.1' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/rtl2830.c:56:1: warning: 'rtl2830_wr' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/rtl2832.c:187:1: warning: 'rtl2832_wr' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/tda10071.c:52:1: warning: 'tda10071_wr_regs' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/tda10071.c:84:1: warning: 'tda10071_rd_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>
Reviewed-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/media/dvb-frontends/af9013.c
drivers/media/dvb-frontends/af9033.c
drivers/media/dvb-frontends/cxd2820r_core.c
drivers/media/dvb-frontends/rtl2830.c
drivers/media/dvb-frontends/rtl2832.c
drivers/media/dvb-frontends/tda10071.c