From: Lucas Denefle <lucas.denefle@xxxxxxxxxxx> [ Upstream commit 41a92a89eee819298f805c40187ad8b02bb53426 ] w1_seq was failing due to several devices responding to the CHAIN_DONE at the same time. Now properly selects the current device in the chain with MATCH_ROM. Also acknowledgment was read twice. Signed-off-by: Lucas Denefle <lucas.denefle@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20220223113558.232750-1-lucas.denefle@xxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/w1/slaves/w1_therm.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c index 259525c3382a..9b9870ba01cd 100644 --- a/drivers/w1/slaves/w1_therm.c +++ b/drivers/w1/slaves/w1_therm.c @@ -690,16 +690,20 @@ static ssize_t w1_seq_show(struct device *device, if (sl->reg_num.id == reg_num->id) seq = i; + if (w1_reset_bus(sl->master)) + goto error; + + /* Put the device into chain DONE state */ + w1_write_8(sl->master, W1_MATCH_ROM); + w1_write_block(sl->master, (u8 *)&rn, 8); w1_write_8(sl->master, W1_42_CHAIN); w1_write_8(sl->master, W1_42_CHAIN_DONE); w1_write_8(sl->master, W1_42_CHAIN_DONE_INV); - w1_read_block(sl->master, &ack, sizeof(ack)); /* check for acknowledgment */ ack = w1_read_8(sl->master); if (ack != W1_42_SUCCESS_CONFIRM_BYTE) goto error; - } /* Exit from CHAIN state */ -- 2.35.1
