[PATCH net v7 2/7] net: mana: fix HWC RQ/SQ buffer size swap
From: Long Li <longli@microsoft.com>
Date: 2026-08-13 17:43:14
Also in:
linux-hyperv, linux-rdma, lkml
Subsystem:
hyper-v/azure core and drivers, networking drivers, networking [general], the rest · Maintainers:
"K. Y. Srinivasan", Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
mana_hwc_init_queues() sized the RQ (which receives responses) with
max_req_msg_size and the SQ (which sends requests) with max_resp_msg_size
-- backwards -- and mana_hwc_rx_event_handler() strided the RQ by
max_req_msg_size when recovering the RX slot index.
This is latent today: the only caller passes equal sizes (both 0x1000)
and the queues are never re-created with the hardware-reported sizes, so
nothing overflows. It would only surface if the two sizes diverged.
Size the RQ by max_resp_msg_size and the SQ by max_req_msg_size, and use
max_resp_msg_size as the RX slot stride.
Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)")
Signed-off-by: Long Li <longli@microsoft.com>
---
Changes since v6:
Commit-message wording only; no code change.
drivers/net/ethernet/microsoft/mana/hw_channel.c | 7 ++++---
include/net/mana/hw_channel.h | 1 +
2 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/microsoft/mana/hw_channel.c b/drivers/net/ethernet/microsoft/mana/hw_channel.c
index b5ed2dbce6ceb7f7a5196dfe5ba3534eb4c5d330..ccef9bf9c6bfde754c28f86103f0b05489091f02 100644
--- a/drivers/net/ethernet/microsoft/mana/hw_channel.c
+++ b/drivers/net/ethernet/microsoft/mana/hw_channel.c@@ -263,7 +263,7 @@ static void mana_hwc_rx_event_handler(void *ctx, u32 gdma_rxq_id, /* Select the RX work request for virtual address and for reposting. */ rq_base_addr = hwc_rxq->msg_buf->mem_info.dma_handle; - rx_req_idx = (sge->address - rq_base_addr) / hwc->max_req_msg_size; + rx_req_idx = (sge->address - rq_base_addr) / hwc->max_resp_msg_size; if (rx_req_idx >= hwc_rxq->msg_buf->num_reqs) { dev_err(hwc->dev, "HWC RX: wrong rx_req_idx=%llu, num_reqs=%u\n",
@@ -737,14 +737,14 @@ static int mana_hwc_init_queues(struct hw_channel_context *hwc, u16 q_depth, goto out; } - err = mana_hwc_create_wq(hwc, GDMA_RQ, q_depth, max_req_msg_size, + err = mana_hwc_create_wq(hwc, GDMA_RQ, q_depth, max_resp_msg_size, hwc->cq, &hwc->rxq); if (err) { dev_err(hwc->dev, "Failed to create HWC RQ: %d\n", err); goto out; } - err = mana_hwc_create_wq(hwc, GDMA_SQ, q_depth, max_resp_msg_size, + err = mana_hwc_create_wq(hwc, GDMA_SQ, q_depth, max_req_msg_size, hwc->cq, &hwc->txq); if (err) { dev_err(hwc->dev, "Failed to create HWC SQ: %d\n", err);
@@ -753,6 +753,7 @@ static int mana_hwc_init_queues(struct hw_channel_context *hwc, u16 q_depth, hwc->num_inflight_msg = q_depth; hwc->max_req_msg_size = max_req_msg_size; + hwc->max_resp_msg_size = max_resp_msg_size; return 0; out:
diff --git a/include/net/mana/hw_channel.h b/include/net/mana/hw_channel.h
index 16feb39616c1bead1a043b3fadc2e18a90651516..73671f479399ac296cf472ec6449e5e6b00a8515 100644
--- a/include/net/mana/hw_channel.h
+++ b/include/net/mana/hw_channel.h@@ -181,6 +181,7 @@ struct hw_channel_context { u16 num_inflight_msg; u32 max_req_msg_size; + u32 max_resp_msg_size; u16 hwc_init_q_depth_max; u32 hwc_init_max_req_msg_size;
--
2.43.0