net: dsa: mt7530: check CORE_PLL_GROUP4 access in mt7531_setup()

mt7531_setup() reads CORE_PLL_GROUP4 through the MT7531 indirect c45
PHY access, modifies it and writes it back to enable the PHY core
PLL, but checks neither the read nor the write. Now that the indirect
access functions propagate command-write failures, a failed read
returns a negative errno that would be bit-modified and written back
into the PLL register, and a failed write-back would go unnoticed.
Check both and bail out. The adjacent EEE advertisement writes push a
constant value and cannot corrupt state, so they are left as is.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/a7dfe3b66ea6ac1ae7915034de0527060e6ddcd4.1785811140.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions