| From 1fbf45a554af85c02e0492f0336880f740186de3 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Wed, 23 Feb 2022 11:35:55 +0000 |
| Subject: w1: w1_therm: fixes w1_seq for ds28ea00 sensors |
| |
| 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 ca70c5f03206..9cbeeb4923ec 100644 |
| --- a/drivers/w1/slaves/w1_therm.c |
| +++ b/drivers/w1/slaves/w1_therm.c |
| @@ -2090,16 +2090,20 @@ 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 |
| |
