From: Sameeh Jubran Date: Mon, 3 Jun 2019 17:43:25 +0300 Subject: [PATCH] net: ena: allow automatic fallback to polling mode Origin: https://git.kernel.org/linus/a4e262cde3cda4491ce666e7c5270954c4d926b9 Bug-Debian: https://bugs.debian.org/941291 Enable fallback to polling mode for Admin queue when identified a command response arrival without an accompanying MSI-X interrupt Signed-off-by: Igor Chauskin Signed-off-by: Sameeh Jubran Signed-off-by: David S. Miller --- drivers/net/ethernet/amazon/ena/ena_com.c | 34 +++++++++++++++++------ drivers/net/ethernet/amazon/ena/ena_com.h | 14 ++++++++++ 2 files changed, 39 insertions(+), 9 deletions(-) Index: linux/drivers/net/ethernet/amazon/ena/ena_com.c =================================================================== --- linux.orig/drivers/net/ethernet/amazon/ena/ena_com.c +++ linux/drivers/net/ethernet/amazon/ena/ena_com.c @@ -762,16 +762,26 @@ static int ena_com_wait_and_process_admi admin_queue->stats.no_completion++; spin_unlock_irqrestore(&admin_queue->q_lock, flags); - if (comp_ctx->status == ENA_CMD_COMPLETED) - pr_err("The ena device have completion but the driver didn't receive any MSI-X interrupt (cmd %d)\n", - comp_ctx->cmd_opcode); - else - pr_err("The ena device doesn't send any completion for the admin cmd %d status %d\n", + if (comp_ctx->status == ENA_CMD_COMPLETED) { + pr_err("The ena device sent a completion but the driver didn't receive a MSI-X interrupt (cmd %d), autopolling mode is %s\n", + comp_ctx->cmd_opcode, + admin_queue->auto_polling ? "ON" : "OFF"); + /* Check if fallback to polling is enabled */ + if (admin_queue->auto_polling) + admin_queue->polling = true; + } else { + pr_err("The ena device doesn't send a completion for the admin cmd %d status %d\n", comp_ctx->cmd_opcode, comp_ctx->status); - - admin_queue->running_state = false; - ret = -ETIME; - goto err; + } + /* Check if shifted to polling mode. + * This will happen if there is a completion without an interrupt + * and autopolling mode is enabled. Continuing normal execution in such case + */ + if (!admin_queue->polling) { + admin_queue->running_state = false; + ret = -ETIME; + goto err; + } } ret = ena_com_comp_status_to_errno(comp_ctx->comp_status); @@ -1650,6 +1660,12 @@ void ena_com_set_admin_polling_mode(stru ena_dev->admin_queue.polling = polling; } +void ena_com_set_admin_auto_polling_mode(struct ena_com_dev *ena_dev, + bool polling) +{ + ena_dev->admin_queue.auto_polling = polling; +} + int ena_com_mmio_reg_read_request_init(struct ena_com_dev *ena_dev) { struct ena_com_mmio_read *mmio_read = &ena_dev->mmio_read; Index: linux/drivers/net/ethernet/amazon/ena/ena_com.h =================================================================== --- linux.orig/drivers/net/ethernet/amazon/ena/ena_com.h +++ linux/drivers/net/ethernet/amazon/ena/ena_com.h @@ -283,6 +283,9 @@ struct ena_com_admin_queue { /* Indicate if the admin queue should poll for completion */ bool polling; + /* Define if fallback to polling mode should occur */ + bool auto_polling; + u16 curr_cmd_id; /* Indicate that the ena was initialized and can @@ -538,6 +541,17 @@ void ena_com_set_admin_polling_mode(stru */ bool ena_com_get_ena_admin_polling_mode(struct ena_com_dev *ena_dev); +/* ena_com_set_admin_auto_polling_mode - Enable autoswitch to polling mode + * @ena_dev: ENA communication layer struct + * @polling: Enable/Disable polling mode + * + * Set the autopolling mode. + * If autopolling is on: + * In case of missing interrupt when data is available switch to polling. + */ +void ena_com_set_admin_auto_polling_mode(struct ena_com_dev *ena_dev, + bool polling); + /* ena_com_admin_q_comp_intr_handler - admin queue interrupt handler * @ena_dev: ENA communication layer struct *