net: dsa: mt7530: error out on failed PHY_IAC command writes

MT7531_PHY_ACS_ST is only ever set by the command write that precedes
each poll in the MT7531 indirect PHY access functions, and that
write's return value is discarded. A failed write leaves ACS_ST at 0
from the previous access, so the poll succeeds on its first iteration
and the functions return stale IAC contents as if they were fresh PHY
data. Check the writes and bail out before polling.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/c34602e63a20ebbfb97babd145c82832d7a0b523.1785811140.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions