The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e50e4f0b85be308a01b830c5fbdffc657e1a6dd0 Mon Sep 17 00:00:00 2001
From: Krzysztof Kozlowski krzk@kernel.org Date: Sun, 20 Sep 2020 23:12:38 +0200 Subject: [PATCH] i2c: imx: Fix external abort on interrupt in exit paths
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 Acked-by: Oleksij Rempel o.rempel@pengutronix.de Signed-off-by: Wolfram Sang wsa@kernel.org
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 63f4367c312b..c98529c76348 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -1169,14 +1169,6 @@ 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);
@@ -1195,6 +1187,14 @@ 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_disable; + } + /* Set up clock divider */ i2c_imx->bitrate = I2C_MAX_STANDARD_MODE_FREQ; ret = of_property_read_u32(pdev->dev.of_node, @@ -1237,13 +1237,12 @@ 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_disable: pm_runtime_put_noidle(&pdev->dev); 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; } @@ -1251,7 +1250,7 @@ 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) @@ -1271,6 +1270,9 @@ 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);