[PATCH 6.6 103/119] i2c: designware: do not hold SCL low when I2C_DYNAMIC_TAR_UPDATE is not set

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



6.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Liu Peibao <loven.liu@xxxxxxxxxxxxxxx>

commit 8de3e97f3d3d62cd9f3067f073e8ac93261597db upstream.

When the Tx FIFO is empty and the last command has no STOP bit
set, the master holds SCL low. If I2C_DYNAMIC_TAR_UPDATE is not
set, BIT(13) MST_ON_HOLD of IC_RAW_INTR_STAT is not enabled,
causing the __i2c_dw_disable() timeout. This is quite similar to
commit 2409205acd3c ("i2c: designware: fix __i2c_dw_disable() in
case master is holding SCL low"). Also check BIT(7)
MST_HOLD_TX_FIFO_EMPTY in IC_STATUS, which is available when
IC_STAT_FOR_CLK_STRETCH is set.

Fixes: 2409205acd3c ("i2c: designware: fix __i2c_dw_disable() in case master is holding SCL low")
Co-developed-by: Xiaowu Ding <xiaowu.ding@xxxxxxxxxxxxxxx>
Signed-off-by: Xiaowu Ding <xiaowu.ding@xxxxxxxxxxxxxxx>
Co-developed-by: Angus Chen <angus.chen@xxxxxxxxxxxxxxx>
Signed-off-by: Angus Chen <angus.chen@xxxxxxxxxxxxxxx>
Signed-off-by: Liu Peibao <loven.liu@xxxxxxxxxxxxxxx>
Acked-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
Signed-off-by: Andi Shyti <andi.shyti@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/i2c/busses/i2c-designware-common.c |    6 ++++--
 drivers/i2c/busses/i2c-designware-core.h   |    1 +
 2 files changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/i2c/busses/i2c-designware-common.c
+++ b/drivers/i2c/busses/i2c-designware-common.c
@@ -442,7 +442,7 @@ err_release_lock:
 void __i2c_dw_disable(struct dw_i2c_dev *dev)
 {
 	struct i2c_timings *t = &dev->timings;
-	unsigned int raw_intr_stats;
+	unsigned int raw_intr_stats, ic_stats;
 	unsigned int enable;
 	int timeout = 100;
 	bool abort_needed;
@@ -450,9 +450,11 @@ void __i2c_dw_disable(struct dw_i2c_dev
 	int ret;
 
 	regmap_read(dev->map, DW_IC_RAW_INTR_STAT, &raw_intr_stats);
+	regmap_read(dev->map, DW_IC_STATUS, &ic_stats);
 	regmap_read(dev->map, DW_IC_ENABLE, &enable);
 
-	abort_needed = raw_intr_stats & DW_IC_INTR_MST_ON_HOLD;
+	abort_needed = (raw_intr_stats & DW_IC_INTR_MST_ON_HOLD) ||
+			(ic_stats & DW_IC_STATUS_MASTER_HOLD_TX_FIFO_EMPTY);
 	if (abort_needed) {
 		if (!(enable & DW_IC_ENABLE_ENABLE)) {
 			regmap_write(dev->map, DW_IC_ENABLE, DW_IC_ENABLE_ENABLE);
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -117,6 +117,7 @@
 #define DW_IC_STATUS_RFNE			BIT(3)
 #define DW_IC_STATUS_MASTER_ACTIVITY		BIT(5)
 #define DW_IC_STATUS_SLAVE_ACTIVITY		BIT(6)
+#define DW_IC_STATUS_MASTER_HOLD_TX_FIFO_EMPTY	BIT(7)
 
 #define DW_IC_SDA_HOLD_RX_SHIFT			16
 #define DW_IC_SDA_HOLD_RX_MASK			GENMASK(23, 16)






[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux