kernel/linux.git/drivers/i2c, branch v6.18.21

i2c: imx: ensure no clock is generated after last read

2026-04-02T11:23:23+00:00

commit 13101db735bdb29c5f60e95fb578690bd178b30f upstream. When reading from the I2DR register, right after releasing the bus by clearing MSTA and MTX, the I2C controller might still generate an additional clock cycle which can cause devices to misbehave. Ensure to only read from I2DR after the bus is not busy anymore. Because this requires polling, the read of the last byte is moved outside of the interrupt handler. An example for such a failing transfer is this: i2ctransfer -y -a 0 w1@0x00 0x02 r1 Error: Sending messages failed: Connection timed out It does not happen with every device because not all devices react to the additional clock cycle. Fixes: 5f5c2d4579ca ("i2c: imx: prevent rescheduling in non dma mode") Cc: stable@vger.kernel.org # v6.13+ Signed-off-by: Stefan Eichenberger Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260218150940.131354-3-eichest@gmail.com Signed-off-by: Greg Kroah-Hartman

i2c: imx: fix i2c issue when reading multiple messages

2026-04-02T11:23:22+00:00

commit f88e2e748a1fc3cb4b8d163a9be790812f578850 upstream. When reading multiple messages, meaning a repeated start is required, polling the bus busy bit must be avoided. This must only be done for the last message. Otherwise, the driver will timeout. Here an example of such a sequence that fails with an error: i2ctransfer -y -a 0 w1@0x00 0x02 r1 w1@0x00 0x02 r1 Error: Sending messages failed: Connection timed out Fixes: 5f5c2d4579ca ("i2c: imx: prevent rescheduling in non dma mode") Cc: stable@vger.kernel.org # v6.13+ Signed-off-by: Stefan Eichenberger Reviewed-by: Frank Li Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260218150940.131354-2-eichest@gmail.com Signed-off-by: Greg Kroah-Hartman

i2c: designware: amdisp: Fix resume-probe race condition issue

2026-04-02T11:23:22+00:00

commit e2f1ada8e089dd5a331bcd8b88125ae2af8d188f upstream. Identified resume-probe race condition in kernel v7.0 with the commit 38fa29b01a6a ("i2c: designware: Combine the init functions"),but this issue existed from the beginning though not detected. The amdisp i2c device requires ISP to be in power-on state for probe to succeed. To meet this requirement, this device is added to genpd to control ISP power using runtime PM. The pm_runtime_get_sync() called before i2c_dw_probe() triggers PM resume, which powers on ISP and also invokes the amdisp i2c runtime resume before the probe completes resulting in this race condition and a NULL dereferencing issue in v7.0 Fix this race condition by using the genpd APIs directly during probe: - Call dev_pm_genpd_resume() to Power ON ISP before probe - Call dev_pm_genpd_suspend() to Power OFF ISP after probe - Set the device to suspended state with pm_runtime_set_suspended() - Enable runtime PM only after the device is fully initialized Fixes: d6263c468a761 ("i2c: amd-isp: Add ISP i2c-designware driver") Co-developed-by: Bin Du Signed-off-by: Bin Du Signed-off-by: Pratap Nirujogi Cc: # v6.16+ Acked-by: Mika Westerberg Reviewed-by: Mario Limonciello (AMD) Reviewed-by: Andy Shevchenko Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260320201302.3490570-1-pratap.nirujogi@amd.com Signed-off-by: Greg Kroah-Hartman

i2c: pxa: defer reset on Armada 3700 when recovery is used

2026-03-25T10:10:44+00:00

commit 78a6ee14f8b9e1c8f7c77612122444f3be8dc8cc upstream. The I2C communication is completely broken on the Armada 3700 platform since commit 0b01392c18b9 ("i2c: pxa: move to generic GPIO recovery"). For example, on the Methode uDPU board, probing of the two onboard temperature sensors fails ... [ 7.271713] i2c i2c-0: using pinctrl states for GPIO recovery [ 7.277503] i2c i2c-0: PXA I2C adapter [ 7.282199] i2c i2c-1: using pinctrl states for GPIO recovery [ 7.288241] i2c i2c-1: PXA I2C adapter [ 7.292947] sfp sfp-eth1: Host maximum power 3.0W [ 7.299614] sfp sfp-eth0: Host maximum power 3.0W [ 7.308178] lm75 1-0048: supply vs not found, using dummy regulator [ 32.489631] lm75 1-0048: probe with driver lm75 failed with error -121 [ 32.496833] lm75 1-0049: supply vs not found, using dummy regulator [ 82.890614] lm75 1-0049: probe with driver lm75 failed with error -121 ... and accessing the plugged-in SFP modules also does not work: [ 511.298537] sfp sfp-eth1: please wait, module slow to respond [ 536.488530] sfp sfp-eth0: please wait, module slow to respond ... [ 1065.688536] sfp sfp-eth1: failed to read EEPROM: -EREMOTEIO [ 1090.888532] sfp sfp-eth0: failed to read EEPROM: -EREMOTEIO After a discussion [1], there was an attempt to fix the problem by reverting the offending change by commit 7b211c767121 ("Revert "i2c: pxa: move to generic GPIO recovery""), but that only helped to fix the issue in the 6.1.y stable tree. The reason behind the partial succes is that there was another change in commit 20cb3fce4d60 ("i2c: Set i2c pinctrl recovery info from it's device pinctrl") in the 6.3-rc1 cycle which broke things further. The cause of the problem is the same in case of both offending commits mentioned above. Namely, the I2C core code changes the pinctrl state to GPIO while running the recovery initialization code. Although the PXA specific initialization also does this, but the key difference is that it happens before the controller is getting enabled in i2c_pxa_reset(), whereas in the case of the generic initialization it happens after that. Change the code to reset the controller only before the first transfer instead of before registering the controller. This ensures that the controller is not enabled at the time when the generic recovery code performs the pinctrl state changes, thus avoids the problem described above. As the result this change restores the original behaviour, which in turn makes the I2C communication to work again as it can be seen from the following log: [ 7.363250] i2c i2c-0: using pinctrl states for GPIO recovery [ 7.369041] i2c i2c-0: PXA I2C adapter [ 7.373673] i2c i2c-1: using pinctrl states for GPIO recovery [ 7.379742] i2c i2c-1: PXA I2C adapter [ 7.384506] sfp sfp-eth1: Host maximum power 3.0W [ 7.393013] sfp sfp-eth0: Host maximum power 3.0W [ 7.399266] lm75 1-0048: supply vs not found, using dummy regulator [ 7.407257] hwmon hwmon0: temp1_input not attached to any thermal zone [ 7.413863] lm75 1-0048: hwmon0: sensor 'tmp75c' [ 7.418746] lm75 1-0049: supply vs not found, using dummy regulator [ 7.426371] hwmon hwmon1: temp1_input not attached to any thermal zone [ 7.432972] lm75 1-0049: hwmon1: sensor 'tmp75c' [ 7.755092] sfp sfp-eth1: module MENTECHOPTO POS22-LDCC-KR rev 1.0 sn MNC208U90009 dc 200828 [ 7.764997] mvneta d0040000.ethernet eth1: unsupported SFP module: no common interface modes [ 7.785362] sfp sfp-eth0: module Mikrotik S-RJ01 rev 1.0 sn 61B103C55C58 dc 201022 [ 7.803426] hwmon hwmon2: temp1_input not attached to any thermal zone Link: https://lore.kernel.org/r/20230926160255.330417-1-robert.marko@sartura.hr #1 Cc: stable@vger.kernel.org # 6.3+ Fixes: 20cb3fce4d60 ("i2c: Set i2c pinctrl recovery info from it's device pinctrl") Signed-off-by: Gabor Juhos Tested-by: Robert Marko Reviewed-by: Linus Walleij Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260226-i2c-pxa-fix-i2c-communication-v4-1-797a091dae87@gmail.com Signed-off-by: Greg Kroah-Hartman

i2c: fsi: Fix a potential leak in fsi_i2c_probe()

2026-03-25T10:10:44+00:00

commit be627abcc0d5dbd5882873bd85fbc18aa3d189ed upstream. In the commit in Fixes:, when the code has been updated to use an explicit for loop, instead of for_each_available_child_of_node(), the assumption that a reference to a device_node structure would be released at each iteration has been broken. Now, an explicit of_node_put() is needed to release the reference. Fixes: 095561f476ab ("i2c: fsi: Create busses for all ports") Signed-off-by: Christophe JAILLET Cc: # v5.3+ Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/fd805c39f8de51edf303856103d782138a1633c8.1772382022.git.christophe.jaillet@wanadoo.fr Signed-off-by: Greg Kroah-Hartman

i2c: cp2615: fix serial string NULL-deref at probe

2026-03-25T10:10:43+00:00

commit aa79f996eb41e95aed85a1bd7f56bcd6a3842008 upstream. The cp2615 driver uses the USB device serial string as the i2c adapter name but does not make sure that the string exists. Verify that the device has a serial number before accessing it to avoid triggering a NULL-pointer dereference (e.g. with malicious devices). Fixes: 4a7695429ead ("i2c: cp2615: add i2c driver for Silicon Labs' CP2615 Digital Audio Bridge") Cc: stable@vger.kernel.org # 5.13 Cc: Bence Csókás Signed-off-by: Johan Hovold Reviewed-by: Bence Csókás Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260309075016.25612-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman

i2c: i801: Revert "i2c: i801: replace acpi_lock with I2C bus lock"

2026-03-12T11:09:56+00:00

[ Upstream commit cfc69c2e6c699c96949f7b0455195b0bfb7dc715 ] This reverts commit f707d6b9e7c18f669adfdb443906d46cfbaaa0c1. Under rare circumstances, multiple udev threads can collect i801 device info on boot and walk i801_acpi_io_handler somewhat concurrently. The first will note the area is reserved by acpi to prevent further touches. This ultimately causes the area to be deregistered. The second will enter i801_acpi_io_handler after the area is unregistered but before a check can be made that the area is unregistered. i2c_lock_bus relies on the now unregistered area containing lock_ops to lock the bus. The end result is a kernel panic on boot with the following backtrace; [ 14.971872] ioatdma 0000:09:00.2: enabling device (0100 -> 0102) [ 14.971873] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 14.971880] #PF: supervisor read access in kernel mode [ 14.971884] #PF: error_code(0x0000) - not-present page [ 14.971887] PGD 0 P4D 0 [ 14.971894] Oops: 0000 [#1] PREEMPT SMP PTI [ 14.971900] CPU: 5 PID: 956 Comm: systemd-udevd Not tainted 5.14.0-611.5.1.el9_7.x86_64 #1 [ 14.971905] Hardware name: XXXXXXXXXXXXXXXXXXXXXXX BIOS 1.20.10.SV91 01/30/2023 [ 14.971908] RIP: 0010:i801_acpi_io_handler+0x2d/0xb0 [i2c_i801] [ 14.971929] Code: 00 00 49 8b 40 20 41 57 41 56 4d 8b b8 30 04 00 00 49 89 ce 41 55 41 89 d5 41 54 49 89 f4 be 02 00 00 00 55 4c 89 c5 53 89 fb <48> 8b 00 4c 89 c7 e8 18 61 54 e9 80 bd 80 04 00 00 00 75 09 4c 3b [ 14.971933] RSP: 0018:ffffbaa841483838 EFLAGS: 00010282 [ 14.971938] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff9685e01ba568 [ 14.971941] RDX: 0000000000000008 RSI: 0000000000000002 RDI: 0000000000000000 [ 14.971944] RBP: ffff9685ca22f028 R08: ffff9685ca22f028 R09: ffff9685ca22f028 [ 14.971948] R10: 000000000000000b R11: 0000000000000580 R12: 0000000000000580 [ 14.971951] R13: 0000000000000008 R14: ffff9685e01ba568 R15: ffff9685c222f000 [ 14.971954] FS: 00007f8287c0ab40(0000) GS:ffff96a47f940000(0000) knlGS:0000000000000000 [ 14.971959] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 14.971963] CR2: 0000000000000000 CR3: 0000000168090001 CR4: 00000000003706f0 [ 14.971966] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 14.971968] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 14.971972] Call Trace: [ 14.971977] [ 14.971981] ? show_trace_log_lvl+0x1c4/0x2df [ 14.971994] ? show_trace_log_lvl+0x1c4/0x2df [ 14.972003] ? acpi_ev_address_space_dispatch+0x16e/0x3c0 [ 14.972014] ? __die_body.cold+0x8/0xd [ 14.972021] ? page_fault_oops+0x132/0x170 [ 14.972028] ? exc_page_fault+0x61/0x150 [ 14.972036] ? asm_exc_page_fault+0x22/0x30 [ 14.972045] ? i801_acpi_io_handler+0x2d/0xb0 [i2c_i801] [ 14.972061] acpi_ev_address_space_dispatch+0x16e/0x3c0 [ 14.972069] ? __pfx_i801_acpi_io_handler+0x10/0x10 [i2c_i801] [ 14.972085] acpi_ex_access_region+0x5b/0xd0 [ 14.972093] acpi_ex_field_datum_io+0x73/0x2e0 [ 14.972100] acpi_ex_read_data_from_field+0x8e/0x230 [ 14.972106] acpi_ex_resolve_node_to_value+0x23d/0x310 [ 14.972114] acpi_ds_evaluate_name_path+0xad/0x110 [ 14.972121] acpi_ds_exec_end_op+0x321/0x510 [ 14.972127] acpi_ps_parse_loop+0xf7/0x680 [ 14.972136] acpi_ps_parse_aml+0x17a/0x3d0 [ 14.972143] acpi_ps_execute_method+0x137/0x270 [ 14.972150] acpi_ns_evaluate+0x1f4/0x2e0 [ 14.972158] acpi_evaluate_object+0x134/0x2f0 [ 14.972164] acpi_evaluate_integer+0x50/0xe0 [ 14.972173] ? vsnprintf+0x24b/0x570 [ 14.972181] acpi_ac_get_state.part.0+0x23/0x70 [ 14.972189] get_ac_property+0x4e/0x60 [ 14.972195] power_supply_show_property+0x90/0x1f0 [ 14.972205] add_prop_uevent+0x29/0x90 [ 14.972213] power_supply_uevent+0x109/0x1d0 [ 14.972222] dev_uevent+0x10e/0x2f0 [ 14.972228] uevent_show+0x8e/0x100 [ 14.972236] dev_attr_show+0x19/0x40 [ 14.972246] sysfs_kf_seq_show+0x9b/0x100 [ 14.972253] seq_read_iter+0x120/0x4b0 [ 14.972262] ? selinux_file_permission+0x106/0x150 [ 14.972273] vfs_read+0x24f/0x3a0 [ 14.972284] ksys_read+0x5f/0xe0 [ 14.972291] do_syscall_64+0x5f/0xe0 ... The kernel panic is mitigated by setting limiting the count of udev children to 1. Revert to using the acpi_lock to continue protecting marking the area as owned by firmware without relying on a lock in a potentially unmapped region of memory. Fixes: f707d6b9e7c1 ("i2c: i801: replace acpi_lock with I2C bus lock") Signed-off-by: Charles Haithcock [wsa: added Fixes-tag and updated comment stating the importance of the lock] Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin

i2c: imx-lpi2c: fix SMBus block read NACK after byte count

2026-03-04T12:21:25+00:00

[ Upstream commit efdc383d1cc28d45cbf5a23b5ffa997010aaacb4 ] The LPI2C controller sends a NACK at the end of a receive command unless another receive command is already queued in MTDR. During SMBus block reads, this causes the controller to NACK immediately after receiving the block length byte, aborting the transfer before the data bytes are read. Fix this by queueing a second receive command as soon as the block length byte is received, keeping MTDR non-empty and ensuring continuous ACKs. The initial receive command reads the block length, and the subsequent command reads the remaining data bytes according to the reported length. Fixes: a55fa9d0e42e ("i2c: imx-lpi2c: add low power i2c bus driver") Signed-off-by: Carlos Song Cc: # v4.10+ Reviewed-by: Frank Li Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260123105459.3448822-1-carlos.song@nxp.com Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin

i2c: imx: preserve error state in block data length handler

2026-02-11T12:42:00+00:00

commit b126097b0327437048bd045a0e4d273dea2910dd upstream. When a block read returns an invalid length, zero or >I2C_SMBUS_BLOCK_MAX, the length handler sets the state to IMX_I2C_STATE_FAILED. However, i2c_imx_master_isr() unconditionally overwrites this with IMX_I2C_STATE_READ_CONTINUE, causing an endless read loop that overruns buffers and crashes the system. Guard the state transition to preserve error states set by the length handler. Fixes: 5f5c2d4579ca ("i2c: imx: prevent rescheduling in non dma mode") Signed-off-by: LI Qingwu Cc: # v6.13+ Reviewed-by: Stefan Eichenberger Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260116111906.3413346-2-Qing-wu.Li@leica-geosystems.com.cn Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman

i2c: spacemit: drop IRQF_ONESHOT flag from IRQ request

2026-01-30T09:32:14+00:00

commit e351836a54e3b0b4483f896abcd6a0dc71097693 upstream. In commit aef30c8d569c ("genirq: Warn about using IRQF_ONESHOT without a threaded handler")[1], it will check IRQF_ONESHOT flag in IRQ request, and gives a warning if there is no threaded handler. Drop this flag to fix this warning. Link: https://lore.kernel.org/r/20260112134013.eQWyReHR@linutronix.de/ [1] Fixes: 5ea558473fa3 ("i2c: spacemit: add support for SpacemiT K1 SoC") Signed-off-by: Yixun Lan Cc: # v6.15+ Reviewed-by: Javier Martinez Canillas Reviewed-by: Troy Mitchell Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260122-05-k1-i2c-irq-v1-1-9b8d94bbcd22@kernel.org Signed-off-by: Greg Kroah-Hartman