Hi Greg, Sasha,
This was missing in 4.9-stable. First patch is only needed so that
applying the second patch becomes easy. If its not accepted I can manually
backport it. Please add it to your queue.
--
Regards
Sudip
>From 266dbff06e2ded50e18e1a3edfbc171ec11235ca Mon Sep 17 00:00:00 2001
From: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
Date: Thu, 8 Mar 2018 14:25:17 +0100
Subject: [PATCH 1/2] i2c: imx: use clk notifier for rate changes
commit 90ad2cbe88c22d0215225ab9594eeead0eb24fde upstream
Instead of repeatedly calling clk_get_rate for each transfer, register
a clock notifier to update the cached divider value each time the clock
rate actually changes.
Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
Reviewed-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
---
drivers/i2c/busses/i2c-imx.c | 32 +++++++++++++++++++++++++-------
1 file changed, 25 insertions(+), 7 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 9c1be9378dfd..4fc8f506e9f1 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -194,6 +194,7 @@ struct imx_i2c_dma {
struct imx_i2c_struct {
struct i2c_adapter adapter;
struct clk *clk;
+ struct notifier_block clk_change_nb;
void __iomem *base;
wait_queue_head_t queue;
unsigned long i2csr;
@@ -468,15 +469,14 @@ static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
return 0;
}
-static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx)
+static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
+ unsigned int i2c_clk_rate)
{
struct imx_i2c_clk_pair *i2c_clk_div = i2c_imx->hwdata->clk_div;
- unsigned int i2c_clk_rate;
unsigned int div;
int i;
/* Divider value calculation */
- i2c_clk_rate = clk_get_rate(i2c_imx->clk);
if (i2c_imx->cur_clk == i2c_clk_rate)
return;
@@ -511,6 +511,20 @@ static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx)
#endif
}
+static int i2c_imx_clk_notifier_call(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct clk_notifier_data *ndata = data;
+ struct imx_i2c_struct *i2c_imx = container_of(&ndata->clk,
+ struct imx_i2c_struct,
+ clk);
+
+ if (action & POST_RATE_CHANGE)
+ i2c_imx_set_clk(i2c_imx, ndata->new_rate);
+
+ return NOTIFY_OK;
+}
+
static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
{
unsigned int temp = 0;
@@ -518,8 +532,6 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
- i2c_imx_set_clk(i2c_imx);
-
imx_i2c_write_reg(i2c_imx->ifdr, i2c_imx, IMX_I2C_IFDR);
/* Enable I2C controller */
imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR);
@@ -1131,6 +1143,9 @@ static int i2c_imx_probe(struct platform_device *pdev)
"clock-frequency", &i2c_imx->bitrate);
if (ret < 0 && pdata && pdata->bitrate)
i2c_imx->bitrate = pdata->bitrate;
+ i2c_imx->clk_change_nb.notifier_call = i2c_imx_clk_notifier_call;
+ clk_notifier_register(i2c_imx->clk, &i2c_imx->clk_change_nb);
+ i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk));
/* Set up chip registers to defaults */
imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
@@ -1141,12 +1156,12 @@ static int i2c_imx_probe(struct platform_device *pdev)
ret = i2c_imx_init_recovery_info(i2c_imx, pdev);
/* Give it another chance if pinctrl used is not ready yet */
if (ret == -EPROBE_DEFER)
- goto rpm_disable;
+ goto clk_notifier_unregister;
/* Add I2C adapter */
ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
if (ret < 0)
- goto rpm_disable;
+ goto clk_notifier_unregister;
pm_runtime_mark_last_busy(&pdev->dev);
pm_runtime_put_autosuspend(&pdev->dev);
@@ -1162,6 +1177,8 @@ static int i2c_imx_probe(struct platform_device *pdev)
return 0; /* Return OK */
+clk_notifier_unregister:
+ clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
rpm_disable:
pm_runtime_put_noidle(&pdev->dev);
pm_runtime_disable(&pdev->dev);
@@ -1195,6 +1212,7 @@ static int i2c_imx_remove(struct platform_device *pdev)
imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2CR);
imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR);
+ clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
clk_disable_unprepare(i2c_imx->clk);
pm_runtime_put_noidle(&pdev->dev);
--
2.11.0
>From 886cadc1c0b701c56e63dcc64080e361a4f6cf13 Mon Sep 17 00:00:00 2001
From: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
Date: Sun, 20 Sep 2020 23:12:38 +0200
Subject: [PATCH 2/2] i2c: imx: Fix external abort on interrupt in exit paths
commit e50e4f0b85be308a01b830c5fbdffc657e1a6dd0 upstream
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@xxxxxxxxxxxxxxx>
Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
Acked-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx>
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
---
drivers/i2c/busses/i2c-imx.c | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 4fc8f506e9f1..5a148b515f3d 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -1111,14 +1111,6 @@ static int i2c_imx_probe(struct platform_device *pdev)
return ret;
}
- /* Request IRQ */
- ret = devm_request_irq(&pdev->dev, irq, i2c_imx_isr, 0,
- 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);
@@ -1137,6 +1129,14 @@ 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 = IMX_I2C_BIT_RATE;
ret = of_property_read_u32(pdev->dev.of_node,
@@ -1179,13 +1179,12 @@ 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;
}
@@ -1193,7 +1192,7 @@ 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)
@@ -1213,6 +1212,9 @@ 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);
--
2.11.0
