[SRU][J:linux-bluefield][PATCH v1 1/1] UBUNTU: SAUCE: gpio-mlxbf3: During reboot test, ipmb driver fails to load intermittently

[Asmaa Mnebhi]

Hi @Tim Gardner<mailto:tim.gardner at canonical.com> @Bartlomiej Zolnierkiewicz<mailto:bartlomiej.zolnierkiewicz at canonical.com>,



Could you please review this patch?



Thanks.
Asmaa



> -----Original Message-----

> From: Asmaa Mnebhi <asmaa at nvidia.com>

> Sent: Monday, May 20, 2024 6:01 PM

> To: kernel-team at lists.ubuntu.com

> Cc: Asmaa Mnebhi <asmaa at nvidia.com>; David Thompson

> <davthompson at nvidia.com>

> Subject: [SRU][J:linux-bluefield][PATCH v1 1/1] UBUNTU: SAUCE: gpio-mlxbf3:

> During reboot test, ipmb driver fails to load intermittently

>

> BugLink: https://bugs.launchpad.net/bugs/2066198

>

> The ipmb driver failing to load is just the result of i2c-mlxbf not receiving

> interrupts.

> In fact, any driver dependent on the i2c-mlxbf driver will not work.

>

> How to reproduce this issue?

>

> - modprobe gpio-mlxbf3

> - modprobe pwr-mlxbf

> - modprobe mlxbf-gige -> this calls into the gpio driver which enables the PHY

> interrupt (gpio10)

> - reboot linux

>   -> graceful reboot does not remove modules so it doesn't disable the PHY

> interrupt via

>      mlxbf3_gpio_irq_disable. Hence, the interrupt remains enabled.

> - In anolis, we don't enforce the dependency between gpio-mlxbf3 and mlxbf-

> gige.

>   So the next time linux boots and loads the driver in this order, we encounter

> the issue:

> - modprobe mlxbf-gige. The gige driver uses polling in the case where it loads

> before the gpio

>   driver. Note that the interrupt at GPIO10 is still enabled at this point so if the

> interrupt

>   triggers, there is nothing to clear it.

> - modprobe gpio-mlxbf3

> - modprobe i2c-mlxbf. The interrupt wouldn't work here because it is shared

> with the gpio

>   interrupts which was not cleared.

>

> The solution is to add a shutdown function to the gpio driver to clear and

> disable all interrupts.

> Also make sure to clear the interrupt after disabling it in the disable irq function.

>

> Signed-off-by: Asmaa Mnebhi <asmaa at nvidia.com<mailto:asmaa at nvidia.com>>

> Reviewed-by: David Thompson <davthompson at nvidia.com<mailto:davthompson at nvidia.com>>

> ---

>  drivers/gpio/gpio-mlxbf3.c | 14 ++++++++++++++

>  1 file changed, 14 insertions(+)

>

> diff --git a/drivers/gpio/gpio-mlxbf3.c b/drivers/gpio/gpio-mlxbf3.c index

> 9d1bd3f6e23f..1646325f1283 100644

> --- a/drivers/gpio/gpio-mlxbf3.c

> +++ b/drivers/gpio/gpio-mlxbf3.c

> @@ -39,6 +39,8 @@

>  #define MLXBF_GPIO_CAUSE_OR_EVTEN0        0x14

>  #define MLXBF_GPIO_CAUSE_OR_CLRCAUSE      0x18

>

> +#define MLXBF_GPIO_CLR_ALL_INTS           0xFFFFFFFF

> +

>  struct mlxbf3_gpio_context {

>            struct gpio_chip gc;

>

> @@ -85,6 +87,8 @@ static void mlxbf3_gpio_irq_disable(struct irq_data *irqd)

>            val = readl(gs->gpio_cause_io + MLXBF_GPIO_CAUSE_OR_EVTEN0);

>            val &= ~BIT(offset);

>            writel(val, gs->gpio_cause_io + MLXBF_GPIO_CAUSE_OR_EVTEN0);

> +

> +         writel(BIT(offset), gs->gpio_cause_io +

> MLXBF_GPIO_CAUSE_OR_CLRCAUSE);

>            raw_spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags);

>

>            gpiochip_disable_irq(gc, offset);

> @@ -267,6 +271,15 @@ static int mlxbf3_gpio_probe(struct platform_device

> *pdev)

>            return 0;

>  }

>

> +static void mlxbf3_gpio_shutdown(struct platform_device *pdev) {

> +         struct mlxbf3_gpio_context *gs = dev_get_drvdata(&pdev->dev);

> +

> +         /* Disable and clear all interrupts */

> +         writel(0, gs->gpio_cause_io + MLXBF_GPIO_CAUSE_OR_EVTEN0);

> +         writel(MLXBF_GPIO_CLR_ALL_INTS, gs->gpio_cause_io +

> +MLXBF_GPIO_CAUSE_OR_CLRCAUSE); }

> +

>  static const struct acpi_device_id mlxbf3_gpio_acpi_match[] = {

>            { "MLNXBF33", 0 },

>            {}

> @@ -279,6 +292,7 @@ static struct platform_driver mlxbf3_gpio_driver = {

>                           .acpi_match_table = mlxbf3_gpio_acpi_match,

>            },

>            .probe    = mlxbf3_gpio_probe,

> +         .shutdown = mlxbf3_gpio_shutdown,

>  };

>  module_platform_driver(mlxbf3_gpio_driver);

>

> --

> 2.30.1


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