linux-stable.git/drivers/i2c, branch v4.19.321 Linux kernel stable tree i2c: riic: avoid potential division by zero 2024-09-04T11:13:00+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2023-09-06T20:00:23+00:00 ce13105a492c91dce263198708b86773569ce370 [ Upstream commit 7890fce6201aed46d3576e3d641f9ee5c1f0e16f ] Value comes from DT, so it could be 0. Unlikely, but could be. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Wolfram Sang <wsa@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 7890fce6201aed46d3576e3d641f9ee5c1f0e16f ]

Value comes from DT, so it could be 0. Unlikely, but could be.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
i2c: smbus: Send alert notifications to all devices if source not found 2024-08-19T03:32:14+00:00 Guenter Roeck linux@roeck-us.net 2024-07-30T14:19:41+00:00 3b20631d0704fe4f6bf4cf9a49fd19871ebaeffb [ Upstream commit f6c29f710c1ff2590109f83be3e212b86c01e0f3 ] If a SMBus alert is received and the originating device is not found, the reason may be that the address reported on the SMBus alert address is corrupted, for example because multiple devices asserted alert and do not correctly implement SMBus arbitration. If this happens, call alert handlers on all devices connected to the given I2C bus, in the hope that this cleans up the situation. This change reliably fixed the problem on a system with multiple devices on a single bus. Example log where the device on address 0x18 (ADM1021) and on address 0x4c (ADT7461A) both had the alert line asserted: smbus_alert 3-000c: SMBALERT# from dev 0x0c, flag 0 smbus_alert 3-000c: no driver alert()! smbus_alert 3-000c: SMBALERT# from dev 0x0c, flag 0 smbus_alert 3-000c: no driver alert()! lm90 3-0018: temp1 out of range, please check! lm90 3-0018: Disabling ALERT# lm90 3-0029: Everything OK lm90 3-002a: Everything OK lm90 3-004c: temp1 out of range, please check! lm90 3-004c: temp2 out of range, please check! lm90 3-004c: Disabling ALERT# Fixes: b5527a7766f0 ("i2c: Add SMBus alert support") Signed-off-by: Guenter Roeck <linux@roeck-us.net> [wsa: fixed a typo in the commit message] Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit f6c29f710c1ff2590109f83be3e212b86c01e0f3 ]

If a SMBus alert is received and the originating device is not found,
the reason may be that the address reported on the SMBus alert address
is corrupted, for example because multiple devices asserted alert and
do not correctly implement SMBus arbitration.

If this happens, call alert handlers on all devices connected to the
given I2C bus, in the hope that this cleans up the situation.

This change reliably fixed the problem on a system with multiple devices
on a single bus. Example log where the device on address 0x18 (ADM1021)
and on address 0x4c (ADT7461A) both had the alert line asserted:

smbus_alert 3-000c: SMBALERT# from dev 0x0c, flag 0
smbus_alert 3-000c: no driver alert()!
smbus_alert 3-000c: SMBALERT# from dev 0x0c, flag 0
smbus_alert 3-000c: no driver alert()!
lm90 3-0018: temp1 out of range, please check!
lm90 3-0018: Disabling ALERT#
lm90 3-0029: Everything OK
lm90 3-002a: Everything OK
lm90 3-004c: temp1 out of range, please check!
lm90 3-004c: temp2 out of range, please check!
lm90 3-004c: Disabling ALERT#

Fixes: b5527a7766f0 ("i2c: Add SMBus alert support")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
[wsa: fixed a typo in the commit message]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
i2c: smbus: Improve handling of stuck alerts 2024-08-19T03:32:14+00:00 Guenter Roeck linux@roeck-us.net 2022-01-10T17:28:56+00:00 9540badee607a99cc07bddbd0a7d4a01fd3b9661 [ Upstream commit 37c526f00bc1c4f847fc800085f8f009d2e11be6 ] The following messages were observed while testing alert functionality on systems with multiple I2C devices on a single bus if alert was active on more than one chip. smbus_alert 3-000c: SMBALERT# from dev 0x0c, flag 0 smbus_alert 3-000c: no driver alert()! and: smbus_alert 3-000c: SMBALERT# from dev 0x28, flag 0 Once it starts, this message repeats forever at high rate. There is no device at any of the reported addresses. Analysis shows that this is seen if multiple devices have the alert pin active. Apparently some devices do not support SMBus arbitration correctly. They keep sending address bits after detecting an address collision and handle the collision not at all or too late. Specifically, address 0x0c is seen with ADT7461A at address 0x4c and ADM1021 at address 0x18 if alert is active on both chips. Address 0x28 is seen with ADT7483 at address 0x2a and ADT7461 at address 0x4c if alert is active on both chips. Once the system is in bad state (alert is set by more than one chip), it often only recovers by power cycling. To reduce the impact of this problem, abort the endless loop in smbus_alert() if the same address is read more than once and not handled by a driver. Fixes: b5527a7766f0 ("i2c: Add SMBus alert support") Signed-off-by: Guenter Roeck <linux@roeck-us.net> [wsa: it also fixed an interrupt storm in one of my experiments] Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com> [wsa: rebased, moved a comment as well, improved the 'invalid' value] Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Stable-dep-of: f6c29f710c1f ("i2c: smbus: Send alert notifications to all devices if source not found") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 37c526f00bc1c4f847fc800085f8f009d2e11be6 ]

The following messages were observed while testing alert functionality
on systems with multiple I2C devices on a single bus if alert was active
on more than one chip.

smbus_alert 3-000c: SMBALERT# from dev 0x0c, flag 0
smbus_alert 3-000c: no driver alert()!

and:

smbus_alert 3-000c: SMBALERT# from dev 0x28, flag 0

Once it starts, this message repeats forever at high rate. There is no
device at any of the reported addresses.

Analysis shows that this is seen if multiple devices have the alert pin
active. Apparently some devices do not support SMBus arbitration correctly.
They keep sending address bits after detecting an address collision and
handle the collision not at all or too late.
Specifically, address 0x0c is seen with ADT7461A at address 0x4c and
ADM1021 at address 0x18 if alert is active on both chips. Address 0x28 is
seen with ADT7483 at address 0x2a and ADT7461 at address 0x4c if alert is
active on both chips.

Once the system is in bad state (alert is set by more than one chip),
it often only recovers by power cycling.

To reduce the impact of this problem, abort the endless loop in
smbus_alert() if the same address is read more than once and not
handled by a driver.

Fixes: b5527a7766f0 ("i2c: Add SMBus alert support")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
[wsa: it also fixed an interrupt storm in one of my experiments]
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
[wsa: rebased, moved a comment as well, improved the 'invalid' value]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Stable-dep-of: f6c29f710c1f ("i2c: smbus: Send alert notifications to all devices if source not found")
Signed-off-by: Sasha Levin <sashal@kernel.org>
i2c: smbus: Don't filter out duplicate alerts 2024-08-19T03:32:13+00:00 Corey Minyard cminyard@mvista.com 2019-11-21T09:10:51+00:00 6adca954fc039151ef4f9c1ea1f201e12a24593d [ Upstream commit dca0dd28fa5e0a1ec41a623dbaf667601fc62331 ] Getting the same alert twice in a row is legal and normal, especially on a fast device (like running in qemu). Kind of like interrupts. So don't report duplicate alerts, and deliver them normally. [JD: Fixed subject] Signed-off-by: Corey Minyard <cminyard@mvista.com> Signed-off-by: Jean Delvare <jdelvare@suse.de> Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Stable-dep-of: f6c29f710c1f ("i2c: smbus: Send alert notifications to all devices if source not found") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit dca0dd28fa5e0a1ec41a623dbaf667601fc62331 ]

Getting the same alert twice in a row is legal and normal,
especially on a fast device (like running in qemu).  Kind of
like interrupts.  So don't report duplicate alerts, and deliver
them normally.

[JD: Fixed subject]

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Stable-dep-of: f6c29f710c1f ("i2c: smbus: Send alert notifications to all devices if source not found")
Signed-off-by: Sasha Levin <sashal@kernel.org>
i2c: rcar: bring hardware to known state when probing 2024-07-18T09:39:39+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2024-07-07T08:28:46+00:00 a291702b35433e4948476b79c034a21fd2b5ebc8 [ Upstream commit 4e36c0f20cb1c74c7bd7ea31ba432c1c4a989031 ] When probing, the hardware is not brought into a known state. This may be a problem when a hypervisor restarts Linux without resetting the hardware, leaving an old state running. Make sure the hardware gets initialized, especially interrupts should be cleared and disabled. Reported-by: Dirk Behme <dirk.behme@de.bosch.com> Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> Closes: https://lore.kernel.org/r/20240702045535.2000393-1-dirk.behme@de.bosch.com Fixes: 6ccbe607132b ("i2c: add Renesas R-Car I2C driver") Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Andi Shyti <andi.shyti@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 4e36c0f20cb1c74c7bd7ea31ba432c1c4a989031 ]

When probing, the hardware is not brought into a known state. This may
be a problem when a hypervisor restarts Linux without resetting the
hardware, leaving an old state running. Make sure the hardware gets
initialized, especially interrupts should be cleared and disabled.

Reported-by: Dirk Behme <dirk.behme@de.bosch.com>
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Closes: https://lore.kernel.org/r/20240702045535.2000393-1-dirk.behme@de.bosch.com
Fixes: 6ccbe607132b ("i2c: add Renesas R-Car I2C driver")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
i2c: pnx: Fix potential deadlock warning from del_timer_sync() call in isr 2024-07-18T09:39:36+00:00 Piotr Wojtaszczyk piotr.wojtaszczyk@timesys.com 2024-06-28T15:25:42+00:00 a349e5ab4dc9954746e836cd10b407ce48f9b2f6 [ Upstream commit f63b94be6942ba82c55343e196bd09b53227618e ] When del_timer_sync() is called in an interrupt context it throws a warning because of potential deadlock. The timer is used only to exit from wait_for_completion() after a timeout so replacing the call with wait_for_completion_timeout() allows to remove the problematic timer and its related functions altogether. Fixes: 41561f28e76a ("i2c: New Philips PNX bus driver") Signed-off-by: Piotr Wojtaszczyk <piotr.wojtaszczyk@timesys.com> Signed-off-by: Andi Shyti <andi.shyti@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit f63b94be6942ba82c55343e196bd09b53227618e ]

When del_timer_sync() is called in an interrupt context it throws a warning
because of potential deadlock. The timer is used only to exit from
wait_for_completion() after a timeout so replacing the call with
wait_for_completion_timeout() allows to remove the problematic timer and
its related functions altogether.

Fixes: 41561f28e76a ("i2c: New Philips PNX bus driver")
Signed-off-by: Piotr Wojtaszczyk <piotr.wojtaszczyk@timesys.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
i2c: i801: Annotate apanel_addr as __ro_after_init 2024-07-18T09:39:33+00:00 Heiner Kallweit hkallweit1@gmail.com 2024-04-12T10:21:58+00:00 1a1f7053437d0f27534ecc9ec7e5d441c082b81c [ Upstream commit 355b1513b1e97b6cef84b786c6480325dfd3753d ] Annotate this variable as __ro_after_init to protect it from being overwritten later. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Andi Shyti <andi.shyti@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 355b1513b1e97b6cef84b786c6480325dfd3753d ]

Annotate this variable as __ro_after_init to protect it from being
overwritten later.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
i2c: ocores: set IACK bit after core is enabled 2024-07-05T07:00:33+00:00 Grygorii Tertychnyi grembeter@gmail.com 2024-05-20T15:39:32+00:00 1f7e4dd58af1267db2970e5c2e98a4d0ff170047 [ Upstream commit 5a72477273066b5b357801ab2d315ef14949d402 ] Setting IACK bit when core is disabled does not clear the "Interrupt Flag" bit in the status register, and the interrupt remains pending. Sometimes it causes failure for the very first message transfer, that is usually a device probe. Hence, set IACK bit after core is enabled to clear pending interrupt. Fixes: 18f98b1e3147 ("[PATCH] i2c: New bus driver for the OpenCores I2C controller") Signed-off-by: Grygorii Tertychnyi <grygorii.tertychnyi@leica-geosystems.com> Acked-by: Peter Korsgaard <peter@korsgaard.com> Cc: stable@vger.kernel.org Signed-off-by: Andi Shyti <andi.shyti@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 5a72477273066b5b357801ab2d315ef14949d402 ]

Setting IACK bit when core is disabled does not clear the "Interrupt Flag"
bit in the status register, and the interrupt remains pending.

Sometimes it causes failure for the very first message transfer, that is
usually a device probe.

Hence, set IACK bit after core is enabled to clear pending interrupt.

Fixes: 18f98b1e3147 ("[PATCH] i2c: New bus driver for the OpenCores I2C controller")
Signed-off-by: Grygorii Tertychnyi <grygorii.tertychnyi@leica-geosystems.com>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Cc: stable@vger.kernel.org
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
i2c: ocores: stop transfer on timeout 2024-07-05T07:00:33+00:00 Federico Vaga federico.vaga@cern.ch 2019-02-14T08:51:30+00:00 c7999d372e7fe8bdfbc2226af1896e8bd328018a [ Upstream commit e7663ef5ae0f02e3b902eb0305dec981333eb3e1 ] Detecting a timeout is ok, but we also need to assert a STOP command on the bus in order to prevent it from generating interrupts when there are no on going transfers. Example: very long transmission. 1. ocores_xfer: START a transfer 2. ocores_isr : handle byte by byte the transfer 3. ocores_xfer: goes in timeout [[bugfix here]] 4. ocores_xfer: return to I2C subsystem and to the I2C driver 5. I2C driver : it may clean up the i2c_msg memory 6. ocores_isr : receives another interrupt (pending bytes to be transferred) but the i2c_msg memory is invalid now So, since the transfer was too long, we have to detect the timeout and STOP the transfer. Another point is that we have a critical region here. When handling the timeout condition we may have a running IRQ handler. For this reason I introduce a spinlock. In order to make easier to understan locking I have: - added a new function to handle timeout - modified the current ocores_process() function in order to be protected by the new spinlock Like this it is obvious at first sight that this locking serializes the execution of ocores_process() and ocores_process_timeout() Signed-off-by: Federico Vaga <federico.vaga@cern.ch> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Stable-dep-of: 5a7247727306 ("i2c: ocores: set IACK bit after core is enabled") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e7663ef5ae0f02e3b902eb0305dec981333eb3e1 ]

Detecting a timeout is ok, but we also need to assert a STOP command on
the bus in order to prevent it from generating interrupts when there are
no on going transfers.

Example: very long transmission.

1. ocores_xfer: START a transfer
2. ocores_isr : handle byte by byte the transfer
3. ocores_xfer: goes in timeout [[bugfix here]]
4. ocores_xfer: return to I2C subsystem and to the I2C driver
5. I2C driver : it may clean up the i2c_msg memory
6. ocores_isr : receives another interrupt (pending bytes to be
                transferred) but the i2c_msg memory is invalid now

So, since the transfer was too long, we have to detect the timeout and
STOP the transfer.

Another point is that we have a critical region here. When handling the
timeout condition we may have a running IRQ handler. For this reason I
introduce a spinlock.

In order to make easier to understan locking I have:
- added a new function to handle timeout
- modified the current ocores_process() function in order to be protected
  by the new spinlock
Like this it is obvious at first sight that this locking serializes
the execution of ocores_process() and ocores_process_timeout()

Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Stable-dep-of: 5a7247727306 ("i2c: ocores: set IACK bit after core is enabled")
Signed-off-by: Sasha Levin <sashal@kernel.org>
i2c: smbus: fix NULL function pointer dereference 2024-05-02T14:17:14+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2024-04-26T06:44:08+00:00 40f1d79f07b49c8a64a861706e5163f2db4bd95d [ Upstream commit 91811a31b68d3765b3065f4bb6d7d6d84a7cfc9f ] Baruch reported an OOPS when using the designware controller as target only. Target-only modes break the assumption of one transfer function always being available. Fix this by always checking the pointer in __i2c_transfer. Reported-by: Baruch Siach <baruch@tkos.co.il> Closes: https://lore.kernel.org/r/4269631780e5ba789cf1ae391eec1b959def7d99.1712761976.git.baruch@tkos.co.il Fixes: 4b1acc43331d ("i2c: core changes for slave support") [wsa: dropped the simplification in core-smbus to avoid theoretical regressions] Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Tested-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 91811a31b68d3765b3065f4bb6d7d6d84a7cfc9f ]

Baruch reported an OOPS when using the designware controller as target
only. Target-only modes break the assumption of one transfer function
always being available. Fix this by always checking the pointer in
__i2c_transfer.

Reported-by: Baruch Siach <baruch@tkos.co.il>
Closes: https://lore.kernel.org/r/4269631780e5ba789cf1ae391eec1b959def7d99.1712761976.git.baruch@tkos.co.il
Fixes: 4b1acc43331d ("i2c: core changes for slave support")
[wsa: dropped the simplification in core-smbus to avoid theoretical regressions]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Sasha Levin <sashal@kernel.org>