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w1: w1_therm: fixes w1_seq for ds28ea00 sensors 

[ Upstream commit 41a92a89ee ]

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>
This commit is contained in:
Lucas Denefle 2022-02-23 11:35:55 +00:00 committed by Greg Kroah-Hartman
parent 197643a60e
commit 3e8a576f2b
1 changed files with 6 additions and 2 deletions
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8
drivers/w1/slaves/w1_therm.c
View File

@ -589,16 +589,20 @@ 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 */