On 11/13/23 04:12, Chris Morgan wrote:
On Sat, Jul 15, 2023 at 09:53:24AM +0200, Benjamin Bara wrote:
From: Benjamin Bara benjamin.bara@skidata.com
Since bae1d3a05a8b, i2c transfers are non-atomic if preemption is disabled. However, non-atomic i2c transfers require preemption (e.g. in wait_for_completion() while waiting for the DMA).
panic() calls preempt_disable_notrace() before calling emergency_restart(). Therefore, if an i2c device is used for the restart, the xfer should be atomic. This avoids warnings like:
[ 12.667612] WARNING: CPU: 1 PID: 1 at kernel/rcu/tree_plugin.h:318 rcu_note_context_switch+0x33c/0x6b0 [ 12.676926] Voluntary context switch within RCU read-side critical section! ... [ 12.742376] schedule_timeout from wait_for_completion_timeout+0x90/0x114 [ 12.749179] wait_for_completion_timeout from tegra_i2c_wait_completion+0x40/0x70 ... [ 12.994527] atomic_notifier_call_chain from machine_restart+0x34/0x58 [ 13.001050] machine_restart from panic+0x2a8/0x32c
Use !preemptible() instead, which is basically the same check as pre-v5.2.
Fixes: bae1d3a05a8b ("i2c: core: remove use of in_atomic()") Cc: stable@vger.kernel.org # v5.2+ Suggested-by: Dmitry Osipenko dmitry.osipenko@collabora.com Acked-by: Wolfram Sang wsa@kernel.org Reviewed-by: Dmitry Osipenko dmitry.osipenko@collabora.com Tested-by: Nishanth Menon nm@ti.com Signed-off-by: Benjamin Bara benjamin.bara@skidata.com
For kernel 6.7 I'm having an issue when I shutdown or reboot my Rockchip RK3326 or Rockchip RK3566 based devices, and I've bisected the issue down to this specific commit.
When I shutdown or restart the device, I receive messages in the kernel log like the following:
[ 37.121148] rk3x-i2c fdd40000.i2c: irq in STATE_IDLE, ipd = 0x3 [ 37.122178] rk3x-i2c fdd40000.i2c: irq in STATE_IDLE, ipd = 0x3 [ 37.123212] rk3x-i2c fdd40000.i2c: irq in STATE_IDLE, ipd = 0x3 [ 37.124226] rk3x-i2c fdd40000.i2c: irq in STATE_IDLE, ipd = 0x3 [ 37.125242] rk3x-i2c fdd40000.i2c: irq in STATE_IDLE, ipd = 0x3 [ 37.126133] rk3x-i2c fdd40000.i2c: irq in STATE_IDLE, ipd = 0x1
The device will also occasionally freeze instead of rebooting or shutting down. The i2c errors are consistent, but the freezing behavior is not.
I couldn't reproduce your issue with v6.7-rc1 and RK3399 that also uses rk3x-i2c. Though, the rk3x-i2c driver looks suspicious. Please try this patch:
diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c index a044ca0c35a1..aad00e9909cc 100644 --- a/drivers/i2c/busses/i2c-rk3x.c +++ b/drivers/i2c/busses/i2c-rk3x.c @@ -219,6 +219,8 @@ struct rk3x_i2c { enum rk3x_i2c_state state; unsigned int processed; int error; + + int irq; };
static inline void i2c_writel(struct rk3x_i2c *i2c, u32 value, @@ -1090,8 +1092,10 @@ static int rk3x_i2c_xfer_common(struct i2c_adapter *adap, rk3x_i2c_start(i2c);
if (!polling) { + enable_irq(i2c->irq); timeout = wait_event_timeout(i2c->wait, !i2c->busy, msecs_to_jiffies(WAIT_TIMEOUT)); + disable_irq(i2c->irq); } else { timeout = rk3x_i2c_wait_xfer_poll(i2c); } @@ -1236,7 +1240,6 @@ static int rk3x_i2c_probe(struct platform_device *pdev) int ret = 0; int bus_nr; u32 value; - int irq; unsigned long clk_rate;
i2c = devm_kzalloc(&pdev->dev, sizeof(struct rk3x_i2c), GFP_KERNEL); @@ -1299,11 +1302,14 @@ static int rk3x_i2c_probe(struct platform_device *pdev) }
/* IRQ setup */ - irq = platform_get_irq(pdev, 0); - if (irq < 0) - return irq; + i2c->irq = platform_get_irq(pdev, 0); + if (i2c->irq < 0) + return i2c->irq; + + /* interrupt will be enabled during of transfer time */ + irq_set_status_flags(i2c->irq, IRQ_NOAUTOEN);
- ret = devm_request_irq(&pdev->dev, irq, rk3x_i2c_irq, + ret = devm_request_irq(&pdev->dev, i2c->irq, rk3x_i2c_irq, 0, dev_name(&pdev->dev), i2c); if (ret < 0) { dev_err(&pdev->dev, "cannot request IRQ\n");