Hi Jyothi, ... > @@ -523,26 +576,49 @@ static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, > enum dma_transfer_direction dma_dirn; > struct dma_async_tx_descriptor *desc; > int ret; > + struct gpi_multi_xfer *gi2c_gpi_xfer; > + dma_cookie_t cookie; > > peripheral = config->peripheral_config; > - > - dma_buf = i2c_get_dma_safe_msg_buf(msg, 1); > - if (!dma_buf) > + gi2c_gpi_xfer = &peripheral->multi_xfer; > + gi2c_gpi_xfer->msg_idx_cnt = cur_msg_idx; > + dma_buf = gi2c_gpi_xfer->dma_buf[gi2c_gpi_xfer->buf_idx]; > + addr = gi2c_gpi_xfer->dma_addr[gi2c_gpi_xfer->buf_idx]; > + > + dma_buf = i2c_get_dma_safe_msg_buf(&msgs[gi2c_gpi_xfer->msg_idx_cnt], 1); > + if (!dma_buf) { > + gi2c->err = -ENOMEM; > return -ENOMEM; > + } > > if (op == I2C_WRITE) > map_dirn = DMA_TO_DEVICE; > else > map_dirn = DMA_FROM_DEVICE; > > - addr = dma_map_single(gi2c->se.dev->parent, dma_buf, msg->len, map_dirn); > + addr = dma_map_single(gi2c->se.dev->parent, > + dma_buf, msgs[gi2c_gpi_xfer->msg_idx_cnt].len, You could save msgs[gi2c_gpi_xfer->msg_idx_cnt] in a separate variable to avoid this extra indexing. > + map_dirn); > if (dma_mapping_error(gi2c->se.dev->parent, addr)) { > - i2c_put_dma_safe_msg_buf(dma_buf, msg, false); > + i2c_put_dma_safe_msg_buf(dma_buf, &msgs[gi2c_gpi_xfer->msg_idx_cnt], > + false); > + gi2c->err = -ENOMEM; > return -ENOMEM; > } > > + if (gi2c->is_tx_multi_xfer) { > + if (((gi2c_gpi_xfer->msg_idx_cnt + 1) % NUM_MSGS_PER_IRQ)) > + peripheral->flags |= QCOM_GPI_BLOCK_EVENT_IRQ; > + else > + peripheral->flags &= ~QCOM_GPI_BLOCK_EVENT_IRQ; > + > + /* BEI bit to be cleared for last TRE */ > + if (gi2c_gpi_xfer->msg_idx_cnt == gi2c->num_msgs - 1) > + peripheral->flags &= ~QCOM_GPI_BLOCK_EVENT_IRQ; > + } > + > /* set the length as message for rx txn */ > - peripheral->rx_len = msg->len; > + peripheral->rx_len = msgs[gi2c_gpi_xfer->msg_idx_cnt].len; > peripheral->op = op; > > ret = dmaengine_slave_config(dma_chan, config); > @@ -560,25 +636,56 @@ static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, > else > dma_dirn = DMA_DEV_TO_MEM; > > - desc = dmaengine_prep_slave_single(dma_chan, addr, msg->len, dma_dirn, flags); > + desc = dmaengine_prep_slave_single(dma_chan, addr, > + msgs[gi2c_gpi_xfer->msg_idx_cnt].len, > + dma_dirn, flags); > if (!desc) { > dev_err(gi2c->se.dev, "prep_slave_sg failed\n"); > - ret = -EIO; > + gi2c->err = -EIO; > goto err_config; > } > > desc->callback_result = i2c_gpi_cb_result; > desc->callback_param = gi2c; > > - dmaengine_submit(desc); > - *buf = dma_buf; > - *dma_addr_p = addr; > + if (!((msgs[cur_msg_idx].flags & I2C_M_RD) && op == I2C_WRITE)) { > + gi2c_gpi_xfer->msg_idx_cnt++; > + gi2c_gpi_xfer->buf_idx = (cur_msg_idx + 1) % QCOM_GPI_MAX_NUM_MSGS; > + } > + cookie = dmaengine_submit(desc); > + if (dma_submit_error(cookie)) { > + dev_err(gi2c->se.dev, > + "%s: dmaengine_submit failed (%d)\n", __func__, cookie); > + return -EINVAL; goto err_config? > + } > > + if (gi2c->is_tx_multi_xfer) { > + dma_async_issue_pending(gi2c->tx_c); > + if ((cur_msg_idx == (gi2c->num_msgs - 1)) || > + (gi2c_gpi_xfer->msg_idx_cnt >= > + QCOM_GPI_MAX_NUM_MSGS + gi2c_gpi_xfer->freed_msg_cnt)) { > + ret = gpi_multi_desc_process(gi2c->se.dev, gi2c_gpi_xfer, > + gi2c->num_msgs, XFER_TIMEOUT, > + &gi2c->done); > + if (ret) { > + dev_dbg(gi2c->se.dev, > + "I2C multi write msg transfer timeout: %d\n", > + ret); if you are returning an error, then print an error. > + gi2c->err = -ETIMEDOUT; gi2c->err = ret? > + goto err_config; > + } > + } > + } else { > + /* Non multi descriptor message transfer */ > + *buf = dma_buf; > + *dma_addr_p = addr; > + } > return 0; > > err_config: > - dma_unmap_single(gi2c->se.dev->parent, addr, msg->len, map_dirn); > - i2c_put_dma_safe_msg_buf(dma_buf, msg, false); > + dma_unmap_single(gi2c->se.dev->parent, addr, > + msgs[cur_msg_idx].len, map_dirn); > + i2c_put_dma_safe_msg_buf(dma_buf, &msgs[cur_msg_idx], false); > return ret; I would have one more label here: out: gi2c->err = ret; return ret; in order to avoid always assigning twice > } > > @@ -590,6 +697,7 @@ static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], i > unsigned long time_left; > dma_addr_t tx_addr, rx_addr; > void *tx_buf = NULL, *rx_buf = NULL; > + struct gpi_multi_xfer *tx_multi_xfer; > const struct geni_i2c_clk_fld *itr = gi2c->clk_fld; > > config.peripheral_config = &peripheral; > @@ -603,6 +711,39 @@ static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], i > peripheral.set_config = 1; > peripheral.multi_msg = false; > > + gi2c->gpi_config = &peripheral; > + gi2c->num_msgs = num; > + gi2c->is_tx_multi_xfer = false; > + gi2c->tx_irq_cnt = 0; > + > + tx_multi_xfer = &peripheral.multi_xfer; > + tx_multi_xfer->msg_idx_cnt = 0; > + tx_multi_xfer->buf_idx = 0; > + tx_multi_xfer->unmap_msg_cnt = 0; > + tx_multi_xfer->freed_msg_cnt = 0; > + tx_multi_xfer->irq_msg_cnt = 0; > + tx_multi_xfer->irq_cnt = 0; you can initialize tx_multi_xfer to "{ };" to avoid all these " = 0" > + > + /* > + * If number of write messages are four and higher then > + * configure hardware for multi descriptor transfers with BEI. > + */ > + if (num >= MIN_NUM_OF_MSGS_MULTI_DESC) { > + gi2c->is_tx_multi_xfer = true; > + for (i = 0; i < num; i++) { > + if (msgs[i].flags & I2C_M_RD) { > + /* > + * Multi descriptor transfer with BEI > + * support is enabled for write transfers. > + * Add BEI optimization support for read > + * transfers later. > + */ > + gi2c->is_tx_multi_xfer = false; > + break; > + } > + } > + } > + > for (i = 0; i < num; i++) { > gi2c->cur = &msgs[i]; > gi2c->err = 0; > @@ -613,14 +754,16 @@ static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], i > peripheral.stretch = 1; > > peripheral.addr = msgs[i].addr; > + if (i > 0 && (!(msgs[i].flags & I2C_M_RD))) > + peripheral.multi_msg = false; > > - ret = geni_i2c_gpi(gi2c, &msgs[i], &config, > + ret = geni_i2c_gpi(gi2c, msgs, i, &config, what is the point of passing 'i' if you always refer to msgs[i] in geni_i2c_gpi()? > &tx_addr, &tx_buf, I2C_WRITE, gi2c->tx_c); > if (ret) > goto err; > > if (msgs[i].flags & I2C_M_RD) { > - ret = geni_i2c_gpi(gi2c, &msgs[i], &config, > + ret = geni_i2c_gpi(gi2c, msgs, i, &config, > &rx_addr, &rx_buf, I2C_READ, gi2c->rx_c); > if (ret) > goto err; > @@ -628,18 +771,28 @@ static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], i > dma_async_issue_pending(gi2c->rx_c); > } > > - dma_async_issue_pending(gi2c->tx_c); > - > - time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT); > - if (!time_left) > - gi2c->err = -ETIMEDOUT; > + if (!gi2c->is_tx_multi_xfer) { > + dma_async_issue_pending(gi2c->tx_c); > + time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT); > + if (!time_left) { > + dev_err(gi2c->se.dev, "%s:I2C timeout\n", __func__); > + gi2c->err = -ETIMEDOUT; > + } > + } > > if (gi2c->err) { > ret = gi2c->err; > goto err; > } > > - geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr); > + if (!gi2c->is_tx_multi_xfer) { > + geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr); > + } else { > + if (gi2c->tx_irq_cnt != tx_multi_xfer->irq_cnt) { else if (...) { ... } Andi