i2c: gpio: fault-injector: add 'inject_panic' injector
Add a fault injector simulating a Kernel panic happening after starting a transfer. Read the docs for its usage. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
parent
63e57b6f19
commit
bb6bdd51c8
|
@ -108,3 +108,29 @@ idle bus is:
|
|||
|
||||
# echo 200 > lose_arbitration &
|
||||
# i2cget -y <bus_to_test> 0x3f
|
||||
|
||||
Panic during transfer
|
||||
=====================
|
||||
|
||||
This fault injector will create a Kernel panic once the master under test
|
||||
started a transfer. This usually means that the state machine of the bus master
|
||||
driver will be ungracefully interrupted and the bus may end up in an unusual
|
||||
state. Use this to check if your shutdown/reboot/boot code can handle this
|
||||
scenario.
|
||||
|
||||
"inject_panic"
|
||||
--------------
|
||||
|
||||
This file is write only and you need to write the delay between the detected
|
||||
start of a transmission and the induced Kernel panic (in µs, maximum is 100ms).
|
||||
The calling process will then sleep and wait for the next bus clock. The
|
||||
process is interruptible, though.
|
||||
|
||||
Start of a transfer is detected by waiting for SCL going down by the master
|
||||
under test. A good starting point for using this fault injector is:
|
||||
|
||||
# echo 0 > inject_panic &
|
||||
# i2cget -y <bus_to_test> <some_address>
|
||||
|
||||
Note that there doesn't need to be a device listening to the address you are
|
||||
using. Results may vary depending on that, though.
|
||||
|
|
|
@ -231,6 +231,32 @@ static int fops_lose_arbitration_set(void *data, u64 duration)
|
|||
}
|
||||
DEFINE_DEBUGFS_ATTRIBUTE(fops_lose_arbitration, NULL, fops_lose_arbitration_set, "%llu\n");
|
||||
|
||||
static irqreturn_t inject_panic_irq(int irq, void *dev_id)
|
||||
{
|
||||
struct i2c_gpio_private_data *priv = dev_id;
|
||||
|
||||
udelay(priv->scl_irq_data);
|
||||
panic("I2C fault injector induced panic");
|
||||
|
||||
return IRQ_HANDLED;
|
||||
}
|
||||
|
||||
static int fops_inject_panic_set(void *data, u64 duration)
|
||||
{
|
||||
struct i2c_gpio_private_data *priv = data;
|
||||
|
||||
if (duration > 100 * 1000)
|
||||
return -EINVAL;
|
||||
|
||||
priv->scl_irq_data = duration;
|
||||
/*
|
||||
* Interrupt on falling SCL. This ensures that the master under test has
|
||||
* really started the transfer.
|
||||
*/
|
||||
return i2c_gpio_fi_act_on_scl_irq(priv, inject_panic_irq);
|
||||
}
|
||||
DEFINE_DEBUGFS_ATTRIBUTE(fops_inject_panic, NULL, fops_inject_panic_set, "%llu\n");
|
||||
|
||||
static void i2c_gpio_fault_injector_init(struct platform_device *pdev)
|
||||
{
|
||||
struct i2c_gpio_private_data *priv = platform_get_drvdata(pdev);
|
||||
|
@ -256,9 +282,12 @@ static void i2c_gpio_fault_injector_init(struct platform_device *pdev)
|
|||
priv, &fops_incomplete_addr_phase);
|
||||
debugfs_create_file_unsafe("incomplete_write_byte", 0200, priv->debug_dir,
|
||||
priv, &fops_incomplete_write_byte);
|
||||
if (priv->bit_data.getscl)
|
||||
if (priv->bit_data.getscl) {
|
||||
debugfs_create_file_unsafe("inject_panic", 0200, priv->debug_dir,
|
||||
priv, &fops_inject_panic);
|
||||
debugfs_create_file_unsafe("lose_arbitration", 0200, priv->debug_dir,
|
||||
priv, &fops_lose_arbitration);
|
||||
}
|
||||
debugfs_create_file_unsafe("scl", 0600, priv->debug_dir, priv, &fops_scl);
|
||||
debugfs_create_file_unsafe("sda", 0600, priv->debug_dir, priv, &fops_sda);
|
||||
}
|
||||
|
|
Loading…
Reference in a new issue