From 030675aa54cf757769b3db65642433d626b3ed7c Mon Sep 17 00:00:00 2001 From: Chaitanya Sabnis Date: Tue, 26 May 2026 15:52:40 +0530 Subject: [PATCH 1/2] i2c: davinci: fix division by zero on missing clock-frequency When the 'clock-frequency' property is missing from the device tree, the driver falls back to DAVINCI_I2C_DEFAULT_BUS_FREQ. However, this macro was defined in kHz (100), whereas the device tree property is expected in Hz. The probe function divided the fallback value by 1000, causing integer truncation that resulted in dev->bus_freq = 0. This triggered a deterministic division-by-zero kernel panic when calculating clock dividers later in the probe sequence. Fix this by redefining DAVINCI_I2C_DEFAULT_BUS_FREQ in Hz (100000) to match the expected device tree property unit, allowing the existing division logic to work correctly for both cases. Fixes: b04ce6385979 ("i2c: davinci: kill platform data") Reported-by: Sashiko Closes: https://lore.kernel.org/all/20260514044726.57297C2BCB7@smtp.kernel.org/ Signed-off-by: Chaitanya Sabnis Cc: # v6.14+ Reviewed-by: Bartosz Golaszewski Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260526102240.4949-1-chaitanya.msabnis@gmail.com --- drivers/i2c/busses/i2c-davinci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index a773ba082321..66c23535656b 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -117,7 +117,7 @@ /* timeout for pm runtime autosuspend */ #define DAVINCI_I2C_PM_TIMEOUT 1000 /* ms */ -#define DAVINCI_I2C_DEFAULT_BUS_FREQ 100 +#define DAVINCI_I2C_DEFAULT_BUS_FREQ 100000 struct davinci_i2c_dev { struct device *dev; From 1d774589f924056b8403e271fdecaf9a803a50fc Mon Sep 17 00:00:00 2001 From: Alexis Bouzigues Date: Fri, 29 May 2026 09:28:14 -0500 Subject: [PATCH 2/2] i2c: virtio: mark device ready before registering the adapter virtio_i2c_probe() synchronously probes child i2c drivers on the bus, but peripherals may use the bus at probe for tasks like reading a chip id. The vhost-user-i2c backend stalls at such probes unless DRIVER_OK is already set before the virtqueue is first kicked. Set DRIVER_OK explicitly before i2c_add_adapter(), as done for the same reason in commit f5866db64f34 ("virtio_console: enable VQs early") and commit 71e4b8bf0482 ("virtio_rpmsg: set DRIVER_OK before using device"). Signed-off-by: Alexis Bouzigues Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-virtio.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/i2c/busses/i2c-virtio.c b/drivers/i2c/busses/i2c-virtio.c index 7b0b0bff8000..5da6fef92bec 100644 --- a/drivers/i2c/busses/i2c-virtio.c +++ b/drivers/i2c/busses/i2c-virtio.c @@ -222,6 +222,8 @@ static int virtio_i2c_probe(struct virtio_device *vdev) */ ACPI_COMPANION_SET(&vi->adap.dev, ACPI_COMPANION(vdev->dev.parent)); + virtio_device_ready(vdev); + ret = i2c_add_adapter(&vi->adap); if (ret) virtio_i2c_del_vqs(vdev);