* [PATCH v2 2/2] i2c: imx: Fix external abort on interrupt in exit paths
2020-06-14 10:29 [PATCH v2 1/2] i2c: imx: Fix PM runtime inbalance in probe error path Krzysztof Kozlowski
@ 2020-06-14 10:29 ` Krzysztof Kozlowski
2020-07-07 18:33 ` Krzysztof Kozlowski
2020-06-15 6:50 ` [PATCH v2 1/2] i2c: imx: Fix PM runtime inbalance in probe error path Krzysztof Kozlowski
1 sibling, 1 reply; 4+ messages in thread
From: Krzysztof Kozlowski @ 2020-06-14 10:29 UTC (permalink / raw)
To: Oleksij Rempel, Pengutronix Kernel Team, Shawn Guo, Sascha Hauer,
Fabio Estevam, NXP Linux Team, Wolfram Sang, linux-i2c,
linux-arm-kernel, linux-kernel
Cc: Oleksij Rempel, Marc Kleine-Budde, stable, Krzysztof Kozlowski
If interrupt comes late, during probe error path or device remove (could
be triggered with CONFIG_DEBUG_SHIRQ), the interrupt handler
i2c_imx_isr() will access registers with the clock being disabled. This
leads to external abort on non-linefetch on Toradex Colibri VF50 module
(with Vybrid VF5xx):
Unhandled fault: external abort on non-linefetch (0x1008) at 0x8882d003
Internal error: : 1008 [#1] ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 5.7.0 #607
Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
(i2c_imx_isr) from [<8017009c>] (free_irq+0x25c/0x3b0)
(free_irq) from [<805844ec>] (release_nodes+0x178/0x284)
(release_nodes) from [<80580030>] (really_probe+0x10c/0x348)
(really_probe) from [<80580380>] (driver_probe_device+0x60/0x170)
(driver_probe_device) from [<80580630>] (device_driver_attach+0x58/0x60)
(device_driver_attach) from [<805806bc>] (__driver_attach+0x84/0xc0)
(__driver_attach) from [<8057e228>] (bus_for_each_dev+0x68/0xb4)
(bus_for_each_dev) from [<8057f3ec>] (bus_add_driver+0x144/0x1ec)
(bus_add_driver) from [<80581320>] (driver_register+0x78/0x110)
(driver_register) from [<8010213c>] (do_one_initcall+0xa8/0x2f4)
(do_one_initcall) from [<80c0100c>] (kernel_init_freeable+0x178/0x1dc)
(kernel_init_freeable) from [<80807048>] (kernel_init+0x8/0x110)
(kernel_init) from [<80100114>] (ret_from_fork+0x14/0x20)
Additionally, the i2c_imx_isr() could wake up the wait queue
(imx_i2c_struct->queue) before its initialization happens.
The resource-managed framework should not be used for interrupt handling,
because the resource will be released too late - after disabling clocks.
The interrupt handler is not prepared for such case.
Fixes: 1c4b6c3bcf30 ("i2c: imx: implement bus recovery")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
Changes since v1:
1. Remove the devm- and use regular methods.
---
drivers/i2c/busses/i2c-imx.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 6e45958565d1..8a0d49419326 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -1171,14 +1171,6 @@ static int i2c_imx_probe(struct platform_device *pdev)
return ret;
}
- /* Request IRQ */
- ret = devm_request_irq(&pdev->dev, irq, i2c_imx_isr, IRQF_SHARED,
- pdev->name, i2c_imx);
- if (ret) {
- dev_err(&pdev->dev, "can't claim irq %d\n", irq);
- goto clk_disable;
- }
-
/* Init queue */
init_waitqueue_head(&i2c_imx->queue);
@@ -1197,6 +1189,14 @@ static int i2c_imx_probe(struct platform_device *pdev)
if (ret < 0)
goto rpm_disable;
+ /* Request IRQ */
+ ret = request_threaded_irq(irq, i2c_imx_isr, NULL, IRQF_SHARED,
+ pdev->name, i2c_imx);
+ if (ret) {
+ dev_err(&pdev->dev, "can't claim irq %d\n", irq);
+ goto rpm_put;
+ }
+
/* Set up clock divider */
i2c_imx->bitrate = I2C_MAX_STANDARD_MODE_FREQ;
ret = of_property_read_u32(pdev->dev.of_node,
@@ -1239,13 +1239,13 @@ static int i2c_imx_probe(struct platform_device *pdev)
clk_notifier_unregister:
clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
+ free_irq(irq, i2c_imx);
+rpm_put:
pm_runtime_put_noidle(&pdev->dev);
rpm_disable:
pm_runtime_disable(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
pm_runtime_dont_use_autosuspend(&pdev->dev);
-
-clk_disable:
clk_disable_unprepare(i2c_imx->clk);
return ret;
}
@@ -1253,7 +1253,7 @@ static int i2c_imx_probe(struct platform_device *pdev)
static int i2c_imx_remove(struct platform_device *pdev)
{
struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
- int ret;
+ int irq, ret;
ret = pm_runtime_get_sync(&pdev->dev);
if (ret < 0)
@@ -1273,6 +1273,9 @@ static int i2c_imx_remove(struct platform_device *pdev)
imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR);
clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
+ irq = platform_get_irq(pdev, 0);
+ if (irq >= 0)
+ free_irq(irq, i2c_imx);
clk_disable_unprepare(i2c_imx->clk);
pm_runtime_put_noidle(&pdev->dev);
--
2.7.4
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^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v2 1/2] i2c: imx: Fix PM runtime inbalance in probe error path
2020-06-14 10:29 [PATCH v2 1/2] i2c: imx: Fix PM runtime inbalance in probe error path Krzysztof Kozlowski
2020-06-14 10:29 ` [PATCH v2 2/2] i2c: imx: Fix external abort on interrupt in exit paths Krzysztof Kozlowski
@ 2020-06-15 6:50 ` Krzysztof Kozlowski
1 sibling, 0 replies; 4+ messages in thread
From: Krzysztof Kozlowski @ 2020-06-15 6:50 UTC (permalink / raw)
To: Oleksij Rempel, Pengutronix Kernel Team, Shawn Guo, Sascha Hauer,
Fabio Estevam, NXP Linux Team, Wolfram Sang, linux-i2c,
linux-arm-kernel, linux-kernel
Cc: Oleksij Rempel, Marc Kleine-Budde, stable
On Sun, Jun 14, 2020 at 12:29:03PM +0200, Krzysztof Kozlowski wrote:
> When pm_runtime_get_sync() fails in probe(), the error path should not
> call pm_runtime_put_noidle(). This would lead to inbalance in
> usage_count.
>
> Fixes: 588eb93ea49f ("i2c: imx: add runtime pm support to improve the performance")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
>
> ---
>
> Changes since v1:
> 1. New patch
This patch is not correct because the runtime usage counter is increased
always, also on failures.
It can be dropped.
Best regards,
Krzysztof
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^ permalink raw reply [flat|nested] 4+ messages in thread