From: Lucas Denefle lucas.denefle@converge.io
[ 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@converge.io Link: https://lore.kernel.org/r/20220223113558.232750-1-lucas.denefle@converge.io Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 3c350dfbcd0b..aba727294bc8 100644 --- a/drivers/w1/slaves/w1_therm.c +++ b/drivers/w1/slaves/w1_therm.c @@ -693,16 +693,20 @@ 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 */