Messages in this thread | | | Date | Fri, 3 Nov 2023 14:59:19 +0200 | Subject | Re: [PATCH v2] i2c: designware: Disable TX_EMPTY irq while waiting for block length byte | From | Jarkko Nikula <> |
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On 11/2/23 05:30, Tam Nguyen wrote: > 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> > --- > v2: > + Reduce the indentations level > + Use regmap_update_bits for bitfield update > + Rewrite comment statement [Serge] > + Update commit message > + Add Co-developed-by tag for co-authors [Andy] > > v1: > https://lore.kernel.org/lkml/avd7jhwexehgbvi6euzdwvf5zvqqgjx4ozo6uxu2qpmlarvva3@sgkce3rvovwk/T/ > --- > drivers/i2c/busses/i2c-designware-master.c | 19 ++++++++++++++++--- > 1 file changed, 16 insertions(+), 3 deletions(-) > Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
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