All of lore.kernel.org
 help / color / mirror / Atom feed
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Ondrej Jirman <megous@megous.com>,
	John Keeping <john@metanate.com>, Wolfram Sang <wsa@kernel.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 04/31] i2c: rk3x: Handle a spurious start completion interrupt flag
Date: Mon, 20 Dec 2021 15:34:04 +0100	[thread overview]
Message-ID: <20211220143020.127663446@linuxfoundation.org> (raw)
In-Reply-To: <20211220143019.974513085@linuxfoundation.org>

From: Ondrej Jirman <megous@megous.com>

[ Upstream commit 02fe0fbd8a21e183687925c3a266ae27dda9840f ]

In a typical read transfer, start completion flag is being set after
read finishes (notice ipd bit 4 being set):

trasnfer poll=0
i2c start
rk3x-i2c fdd40000.i2c: IRQ: state 1, ipd: 10
i2c read
rk3x-i2c fdd40000.i2c: IRQ: state 2, ipd: 1b
i2c stop
rk3x-i2c fdd40000.i2c: IRQ: state 4, ipd: 33

This causes I2C transfer being aborted in polled mode from a stop completion
handler:

trasnfer poll=1
i2c start
rk3x-i2c fdd40000.i2c: IRQ: state 1, ipd: 10
i2c read
rk3x-i2c fdd40000.i2c: IRQ: state 2, ipd: 0
rk3x-i2c fdd40000.i2c: IRQ: state 2, ipd: 1b
i2c stop
rk3x-i2c fdd40000.i2c: IRQ: state 4, ipd: 13
i2c stop
rk3x-i2c fdd40000.i2c: unexpected irq in STOP: 0x10

Clearing the START flag after read fixes the issue without any obvious
side effects.

This issue was dicovered on RK3566 when adding support for powering
off the RK817 PMIC.

Signed-off-by: Ondrej Jirman <megous@megous.com>
Reviewed-by: John Keeping <john@metanate.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/busses/i2c-rk3x.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index df220666d6274..b4f8cd7dc8b74 100644
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -424,8 +424,8 @@ static void rk3x_i2c_handle_read(struct rk3x_i2c *i2c, unsigned int ipd)
 	if (!(ipd & REG_INT_MBRF))
 		return;
 
-	/* ack interrupt */
-	i2c_writel(i2c, REG_INT_MBRF, REG_IPD);
+	/* ack interrupt (read also produces a spurious START flag, clear it too) */
+	i2c_writel(i2c, REG_INT_MBRF | REG_INT_START, REG_IPD);
 
 	/* Can only handle a maximum of 32 bytes at a time */
 	if (len > 32)
-- 
2.33.0




  parent reply	other threads:[~2021-12-20 14:38 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-20 14:34 [PATCH 4.9 00/31] 4.9.294-rc1 review Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 01/31] nfc: fix segfault in nfc_genl_dump_devices_done Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 02/31] net/mlx4_en: Update reported link modes for 1/10G Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 03/31] parisc/agp: Annotate parisc agp init functions with __init Greg Kroah-Hartman
2021-12-20 14:34 ` Greg Kroah-Hartman [this message]
2021-12-20 14:34 ` [PATCH 4.9 05/31] net: netlink: af_netlink: Prevent empty skb by adding a check on len Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 06/31] tracing: Fix a kmemleak false positive in tracing_map Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 07/31] hwmon: (dell-smm) Fix warning on /proc/i8k creation error Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 08/31] mac80211: send ADDBA requests using the tid/queue of the aggregation session Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 09/31] recordmcount.pl: look for jgnop instruction as well as bcrl on s390 Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 10/31] dm btree remove: fix use after free in rebalance_children() Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 11/31] nfsd: fix use-after-free due to delegation race Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 12/31] soc/tegra: fuse: Fix bitwise vs. logical OR warning Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 13/31] igbvf: fix double free in `igbvf_probe` Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 14/31] ixgbe: set X550 MDIO speed before talking to PHY Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 15/31] USB: gadget: bRequestType is a bitfield, not a enum Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 16/31] PCI/MSI: Clear PCI_MSIX_FLAGS_MASKALL on error Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 17/31] USB: serial: option: add Telit FN990 compositions Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 18/31] timekeeping: Really make sure wall_to_monotonic isnt positive Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 19/31] net: systemport: Add global locking for descriptor lifecycle Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 20/31] firmware: arm_scpi: Fix string overflow in SCPI genpd driver Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 21/31] fuse: annotate lock in fuse_reverse_inval_entry() Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 22/31] scsi: scsi_debug: Sanity check block descriptor length in resp_mode_select() Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 23/31] net: lan78xx: Avoid unnecessary self assignment Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 24/31] ARM: 8805/2: remove unneeded naked function usage Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 25/31] mwifiex: Remove unnecessary braces from HostCmd_SET_SEQ_NO_BSS_INFO Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 26/31] Input: touchscreen - avoid bitwise vs logical OR warning Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 27/31] xen/blkfront: harden blkfront against event channel storms Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 28/31] xen/netfront: harden netfront " Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 29/31] xen/console: harden hvc_xen " Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 30/31] xen/netback: fix rx queue stall detection Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 4.9 31/31] xen/netback: dont queue unlimited number of packages Greg Kroah-Hartman
2021-12-20 17:22 ` [PATCH 4.9 00/31] 4.9.294-rc1 review Florian Fainelli
2021-12-20 18:25 ` Jon Hunter
2021-12-20 23:19 ` Shuah Khan
2021-12-21 17:33 ` Naresh Kamboju
2021-12-21 23:12 ` Guenter Roeck

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20211220143020.127663446@linuxfoundation.org \
    --to=gregkh@linuxfoundation.org \
    --cc=john@metanate.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=megous@megous.com \
    --cc=sashal@kernel.org \
    --cc=stable@vger.kernel.org \
    --cc=wsa@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.