linux-kernel - [PATCH 04/12] i2c: xiic: Add wait for FIFO empty in send

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 24 Jun 2022 17:35:19 +0530
From:   Manikanta Guntupalli <manikanta.guntupalli@...inx.com>
To:     <michal.simek@...inx.com>, <michal.simek@....com>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-i2c@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <git@....com>
CC:     Raviteja Narayanam <raviteja.narayanam@...inx.com>,
        Manikanta Guntupalli <manikanta.guntupalli@...inx.com>
Subject: [PATCH 04/12] i2c: xiic: Add wait for FIFO empty in send_tx

From: Raviteja Narayanam <raviteja.narayanam@...inx.com>

If the tx_half_empty interrupt comes first instead of tx_empty,
STOP bit is generated even before all the bytes are transmitted
out on the bus.
STOP bit should be sent only after all the bytes in the FIFO are
transmitted out of the FIFO. So wait until FIFO is empty before sending
the STOP bit.

Signed-off-by: Raviteja Narayanam <raviteja.narayanam@...inx.com>
Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@...inx.com>
---
 drivers/i2c/busses/i2c-xiic.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c
index 2d5214f1ba03..9c3266ac209e 100644
--- a/drivers/i2c/busses/i2c-xiic.c
+++ b/drivers/i2c/busses/i2c-xiic.c
@@ -472,6 +472,12 @@ static void xiic_send_tx(struct xiic_i2c *i2c)
 
 		if (i2c->nmsgs == 1) {
 			u8 cr;
+			int status;
+
+			/* Wait till FIFO is empty so STOP is sent last */
+			status = xiic_wait_tx_empty(i2c);
+			if (status)
+				return;
 
 			/* Write to CR to stop */
 			cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET);
-- 
2.25.1