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Date: Mon, 3 Apr 2017 12:27:04 +0100
From: Lee Jones <lee.jones@...aro.org>
To: Tony Lindgren <tony@...mide.com>
Cc: Mark Brown <broonie@...nel.org>, linux-kernel@...r.kernel.org,
linux-omap@...r.kernel.org,
Charles Keepax <ckeepax@...nsource.wolfsonmicro.com>,
Marcel Partap <mpartap@....net>,
Michael Scott <michael.scott@...aro.org>
Subject: Re: [PATCH 1/4] regmap: irq: Fix lost interrupts by introducing
handle_reread
On Wed, 22 Mar 2017, Tony Lindgren wrote:
> At least Motorola CPCAP PMIC needs it's device interrupts re-read
> until there are no more interrupts. Otherwise the PMIC interrupt to
> the SoC will eventually stop toggling. This seems to be a bug in the
> CPCAP PMIC where it can stop driving the GPIO interrupt to the SoC
> with pending CPCAP interrupts.
>
> Let's allow handling issues like this by introducing a flag for
> handle_reread and by splitting regmap_irq_thread() into two separate
> functions for regmap_read_irq_status() and regmap_irq_handle_pending().
>
> Cc: Charles Keepax <ckeepax@...nsource.wolfsonmicro.com>
> Cc: Lee Jones <lee.jones@...aro.org>
> Cc: Marcel Partap <mpartap@....net>
> Cc: Michael Scott <michael.scott@...aro.org>
> Tested-by: Sebastian Reichel <sre@...nel.org>
> Signed-off-by: Tony Lindgren <tony@...mide.com>
> ---
> drivers/base/regmap/regmap-irq.c | 77 +++++++++++++++++++++++++++-------------
> include/linux/regmap.h | 2 ++
> 2 files changed, 55 insertions(+), 24 deletions(-)
Looks like this is required for the MFD patches.
I'm removing them for now.
> diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
> --- a/drivers/base/regmap/regmap-irq.c
> +++ b/drivers/base/regmap/regmap-irq.c
> @@ -259,27 +259,11 @@ static const struct irq_chip regmap_irq_chip = {
> .irq_set_wake = regmap_irq_set_wake,
> };
>
> -static irqreturn_t regmap_irq_thread(int irq, void *d)
> +static int regmap_read_irq_status(struct regmap_irq_chip_data *data)
> {
> - struct regmap_irq_chip_data *data = d;
> const struct regmap_irq_chip *chip = data->chip;
> struct regmap *map = data->map;
> int ret, i;
> - bool handled = false;
> - u32 reg;
> -
> - if (chip->handle_pre_irq)
> - chip->handle_pre_irq(chip->irq_drv_data);
> -
> - if (chip->runtime_pm) {
> - ret = pm_runtime_get_sync(map->dev);
> - if (ret < 0) {
> - dev_err(map->dev, "IRQ thread failed to resume: %d\n",
> - ret);
> - pm_runtime_put(map->dev);
> - goto exit;
> - }
> - }
>
> /*
> * Read in the statuses, using a single bulk read if possible
> @@ -299,7 +283,7 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
> if (ret != 0) {
> dev_err(map->dev, "Failed to read IRQ status: %d\n",
> ret);
> - goto exit;
> + return ret;
> }
>
> for (i = 0; i < data->chip->num_regs; i++) {
> @@ -315,7 +299,7 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
> break;
> default:
> BUG();
> - goto exit;
> + return ret;
> }
> }
>
> @@ -330,13 +314,21 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
> dev_err(map->dev,
> "Failed to read IRQ status: %d\n",
> ret);
> - if (chip->runtime_pm)
> - pm_runtime_put(map->dev);
> - goto exit;
> + return ret;
> }
> }
> }
>
> + return 0;
> +}
> +
> +static int regmap_irq_handle_pending(struct regmap_irq_chip_data *data)
> +{
> + const struct regmap_irq_chip *chip = data->chip;
> + struct regmap *map = data->map;
> + int ret, i, handled = 0;
> + u32 reg;
> +
> /*
> * Ignore masked IRQs and ack if we need to; we ack early so
> * there is no race between handling and acknowleding the
> @@ -361,14 +353,51 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
> if (data->status_buf[chip->irqs[i].reg_offset /
> map->reg_stride] & chip->irqs[i].mask) {
> handle_nested_irq(irq_find_mapping(data->domain, i));
> - handled = true;
> + handled++;
> + }
> + }
> +
> + return handled;
> +}
> +
> +static irqreturn_t regmap_irq_thread(int irq, void *d)
> +{
> + struct regmap_irq_chip_data *data = d;
> + const struct regmap_irq_chip *chip = data->chip;
> + struct regmap *map = data->map;
> + int ret, handled = 0;
> +
> + if (chip->handle_pre_irq)
> + chip->handle_pre_irq(chip->irq_drv_data);
> +
> + if (chip->runtime_pm) {
> + ret = pm_runtime_get_sync(map->dev);
> + if (ret < 0) {
> + dev_err(map->dev, "IRQ thread failed to resume: %d\n",
> + ret);
> + goto out_runtime_put;
> }
> }
>
> + do {
> + ret = regmap_read_irq_status(data);
> + if (ret)
> + goto out_runtime_put;
> +
> + ret = regmap_irq_handle_pending(data);
> + if (ret < 0)
> + goto out_runtime_put;
> +
> + if (!ret)
> + break;
> +
> + handled += ret;
> + } while (chip->handle_reread);
> +
> +out_runtime_put:
> if (chip->runtime_pm)
> pm_runtime_put(map->dev);
>
> -exit:
> if (chip->handle_post_irq)
> chip->handle_post_irq(chip->irq_drv_data);
>
> diff --git a/include/linux/regmap.h b/include/linux/regmap.h
> --- a/include/linux/regmap.h
> +++ b/include/linux/regmap.h
> @@ -897,6 +897,7 @@ struct regmap_irq {
> * @ack_invert: Inverted ack register: cleared bits for ack.
> * @wake_invert: Inverted wake register: cleared bits are wake enabled.
> * @type_invert: Invert the type flags.
> + * @handle_reread: Read interrupt status until no more interrupts are seen.
> * @runtime_pm: Hold a runtime PM lock on the device when accessing it.
> *
> * @num_regs: Number of registers in each control bank.
> @@ -934,6 +935,7 @@ struct regmap_irq_chip {
> bool wake_invert:1;
> bool runtime_pm:1;
> bool type_invert:1;
> + bool handle_reread:1;
>
> int num_regs;
>
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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