On Thu, Sep 25, 2025 at 05:30:34PM +0530, Jyothi Kumar Seerapu wrote: > From: Jyothi Kumar Seerapu <[email protected]> > > GSI hardware generates an interrupt for each transfer completion. > For multiple messages within a single transfer, this results in > N interrupts for N messages, leading to significant software > interrupt latency. > > To mitigate this latency, utilize Block Event Interrupt (BEI) mechanism. > Enabling BEI instructs the GSI hardware to prevent interrupt generation > and BEI is disabled when an interrupt is necessary. > > Large I2C transfer can be divided into chunks of messages internally. > Interrupts are not expected for the messages for which BEI bit set, > only the last message triggers an interrupt, indicating the completion of > N messages. This BEI mechanism enhances overall transfer efficiency. > > Signed-off-by: Jyothi Kumar Seerapu <[email protected]> > --- > > v7 -> v8: > - Removed duplicate sentence in commit description > > v6 -> v7: > - The design has been modified to configure BEI for interrupt > generation either: > After the last I2C message, if sufficient TREs are available, or > After a specific I2C message, when no further TREs are available. > - In the GPI driver, passed the flags argumnetr to the gpi_create_i2c_tre > function > and so avoided using external variables for DMA_PREP_INTERRUPT status. > > v5 ->v6: > - For updating the block event interrupt bit, instead of relying on > bei_flag, decision check is moved with DMA_PREP_INTERRUPT flag. > > v4 -> v5: > - BEI flag naming changed from flags to bei_flag. > - QCOM_GPI_BLOCK_EVENT_IRQ macro is removed from qcom-gpi-dma.h > file, and Block event interrupt support is checked with bei_flag. > > v3 -> v4: > - API's added for Block event interrupt with multi descriptor support for > I2C is moved from qcom-gpi-dma.h file to I2C geni qcom driver file. > - gpi_multi_xfer_timeout_handler function is moved from GPI driver to > I2C driver. > > v2-> v3: > - Renamed gpi_multi_desc_process to gpi_multi_xfer_timeout_handler > - MIN_NUM_OF_MSGS_MULTI_DESC changed from 4 to 2 > - Added documentation for newly added changes in "qcom-gpi-dma.h" file > - Updated commit description. > > v1 -> v2: > - Changed dma_addr type from array of pointers to array. > - To support BEI functionality with the TRE size of 64 defined in GPI > driver, > updated QCOM_GPI_MAX_NUM_MSGS to 16 and NUM_MSGS_PER_IRQ to 4. > > drivers/dma/qcom/gpi.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) >
Reviewed-by: Dmitry Baryshkov <[email protected]> -- With best wishes Dmitry
