11.01.2021 16:55, Mikko Perttunen пишет:

quoted

Upon a communication error, the interrupt handler can call
tegra_i2c_disable_packet_mode. This causes a sleeping poll to happen
unless the current transaction was marked atomic. Since
tegra_i2c_disable_packet_mode is only called from the interrupt path,
make it use atomic waiting always.

Fixes: ede2299f7101 ("i2c: tegra: Support atomic transfers")
Cc: stable@vger.kernel.org
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
---
This fixes constant spew for me while HDMI is connected to a
powered off television.

  drivers/i2c/busses/i2c-tegra.c | 16 ++++++++--------
  1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 6f08c0c3238d..4a7ff1840565 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c

@@ -528,12 +528,12 @@ static void tegra_i2c_vi_init(struct tegra_i2c_dev *i2c_dev)
  
  static int tegra_i2c_poll_register(struct tegra_i2c_dev *i2c_dev,
  				   u32 reg, u32 mask, u32 delay_us,
-				   u32 timeout_us)
+				   u32 timeout_us, bool force_atomic)
  {
  	void __iomem *addr = i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg);
  	u32 val;
  
-	if (!i2c_dev->atomic_mode)
+	if (!i2c_dev->atomic_mode && !force_atomic)
  		return readl_relaxed_poll_timeout(addr, val, !(val & mask),
  						  delay_us, timeout_us);
  

@@ -560,7 +560,7 @@ static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
  	val |= mask;
  	i2c_writel(i2c_dev, val, offset);
  
-	err = tegra_i2c_poll_register(i2c_dev, offset, mask, 1000, 1000000);
+	err = tegra_i2c_poll_register(i2c_dev, offset, mask, 1000, 1000000, false);
  	if (err) {
  		dev_err(i2c_dev->dev, "failed to flush FIFO\n");
  		return err;

@@ -569,7 +569,7 @@ static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
  	return 0;
  }
  
-static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
+static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev, bool force_atomic)
  {
  	int err;
  

@@ -579,7 +579,7 @@ static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
  	i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD);
  
  	err = tegra_i2c_poll_register(i2c_dev, I2C_CONFIG_LOAD, 0xffffffff,
-				      1000, I2C_CONFIG_LOAD_TIMEOUT);
+				      1000, I2C_CONFIG_LOAD_TIMEOUT, force_atomic);
  	if (err) {
  		dev_err(i2c_dev->dev, "failed to load config\n");
  		return err;

@@ -684,7 +684,7 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
  	if (i2c_dev->multimaster_mode && i2c_dev->hw->has_slcg_override_reg)
  		i2c_writel(i2c_dev, I2C_MST_CORE_CLKEN_OVR, I2C_CLKEN_OVERRIDE);
  
-	err = tegra_i2c_wait_for_config_load(i2c_dev);
+	err = tegra_i2c_wait_for_config_load(i2c_dev, false);
  	if (err)
  		return err;
  

@@ -707,7 +707,7 @@ static int tegra_i2c_disable_packet_mode(struct tegra_i2c_dev *i2c_dev)
  	if (cnfg & I2C_CNFG_PACKET_MODE_EN)
  		i2c_writel(i2c_dev, cnfg & ~I2C_CNFG_PACKET_MODE_EN, I2C_CNFG);
  
-	return tegra_i2c_wait_for_config_load(i2c_dev);
+	return tegra_i2c_wait_for_config_load(i2c_dev, true);
  }
  
  static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)

@@ -1090,7 +1090,7 @@ static int tegra_i2c_issue_bus_clear(struct i2c_adapter *adap)
  	      I2C_BC_TERMINATE;
  	i2c_writel(i2c_dev, val, I2C_BUS_CLEAR_CNFG);
  
-	err = tegra_i2c_wait_for_config_load(i2c_dev);
+	err = tegra_i2c_wait_for_config_load(i2c_dev, false);
  	if (err)
  		return err;
  

What about a simpler variant:

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 6f08c0c3238d..0727383f4940 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c

@@ -533,7 +533,7 @@ static int tegra_i2c_poll_register(struct

tegra_i2c_dev *i2c_dev,
  	void __iomem *addr = i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg);
  	u32 val;

-	if (!i2c_dev->atomic_mode)
+	if (!i2c_dev->atomic_mode && !in_irq())
  		return readl_relaxed_poll_timeout(addr, val, !(val & mask),
  						  delay_us, timeout_us);