linux/drivers/i2c
Tam Nguyen e8183fa10c i2c: designware: Disable TX_EMPTY irq while waiting for block length byte
During SMBus block data read process, we have seen high interrupt rate
because of TX_EMPTY irq status while waiting for block length byte (the
first data byte after the address phase). The interrupt handler does not
do anything because the internal state is kept as STATUS_WRITE_IN_PROGRESS.
Hence, we should disable TX_EMPTY IRQ until I2C DesignWare receives
first data byte from I2C device, then re-enable it to resume SMBus
transaction.

It takes 0.789 ms for host to receive data length from slave.
Without the patch, i2c_dw_isr() is called 99 times by TX_EMPTY interrupt.
And it is none after applying the patch.

Cc: stable@vger.kernel.org
Co-developed-by: Chuong Tran <chuong@os.amperecomputing.com>
Signed-off-by: Chuong Tran <chuong@os.amperecomputing.com>
Signed-off-by: Tam Nguyen <tamnguyenchi@os.amperecomputing.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2023-11-08 10:19:48 +01:00
..
algos i2c: algo: bit: allow getsda to be NULL 2023-01-23 23:15:49 +01:00
busses i2c: designware: Disable TX_EMPTY irq while waiting for block length byte 2023-11-08 10:19:48 +01:00
muxes I2C has largely driver updates for 6.7., i.e. feature additions (like 2023-11-05 08:41:14 -10:00
i2c-atr.c i2c: Annotate struct i2c_atr with __counted_by 2023-09-24 22:50:25 +02:00
i2c-boardinfo.c
i2c-core-acpi.c i2c: add fwnode APIs 2023-01-17 09:29:59 +01:00
i2c-core-base.c i2c: core: fix lockdep warning for sparsely nested adapter chain 2023-10-28 14:47:49 +02:00
i2c-core-of.c Char/Misc drivers for 6.4-rc1 2023-04-27 12:07:50 -07:00
i2c-core-slave.c i2c: add tracepoints for I2C slave events 2022-03-20 00:11:05 +01:00
i2c-core-smbus.c i2c: smbus: Check for parent device before dereference 2022-02-19 12:37:20 +01:00
i2c-core.h i2c: core: Run atomic i2c xfer when !preemptible 2023-07-28 11:33:02 +01:00
i2c-dev.c i2c: dev: make i2c_dev_class a static const structure 2023-09-19 22:09:58 +02:00
i2c-mux.c i2c: mux: Avoid potential false error message in i2c_mux_add_adapter 2023-09-25 08:22:02 +02:00
i2c-slave-eeprom.c i2c: Convert drivers to new .probe() callback 2023-03-09 21:59:30 +01:00
i2c-slave-testunit.c i2c: Convert drivers to new .probe() callback 2023-03-09 21:59:30 +01:00
i2c-smbus.c i2c: Convert drivers to new .probe() callback 2023-03-09 21:59:30 +01:00
i2c-stub.c
Kconfig i2c: Make I2C_ATR invisible 2023-09-13 10:56:00 +02:00
Makefile media: i2c: add I2C Address Translator (ATR) support 2023-07-14 13:11:44 +02:00