Re: [RFC 06/19] staging: qlge: disable flow control by default
From: Benjamin Poirier <hidden>
Date: 2021-06-22 07:50:01
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On 2021-06-21 21:48 +0800, Coiby Xu wrote:
quoted hunk ↗ jump to hunk
According to the TODO item,quoted
* the flow control implementation in firmware is buggy (sends a flood of pause frames, resets the link, device and driver buffer queues become desynchronized), disable it by defaultCurrently, qlge_mpi_port_cfg_work calls qlge_mb_get_port_cfg which gets the link config from the firmware and saves it to qdev->link_config. By default, flow control is enabled. This commit writes the save the pause parameter of qdev->link_config and don't let it overwritten by link settings of current port. Since qdev->link_config=0 when qdev is initialized, this could disable flow control by default and the pause parameter value could also survive MPI resetting, $ ethtool -a enp94s0f0 Pause parameters for enp94s0f0: Autonegotiate: off RX: off TX: off The follow control can be enabled manually, $ ethtool -A enp94s0f0 rx on tx on $ ethtool -a enp94s0f0 Pause parameters for enp94s0f0: Autonegotiate: off RX: on TX: on Signed-off-by: Coiby Xu <redacted> --- drivers/staging/qlge/TODO | 3 --- drivers/staging/qlge/qlge_mpi.c | 11 ++++++++++- 2 files changed, 10 insertions(+), 4 deletions(-)diff --git a/drivers/staging/qlge/TODO b/drivers/staging/qlge/TODO index b7a60425fcd2..8c84160b5993 100644 --- a/drivers/staging/qlge/TODO +++ b/drivers/staging/qlge/TODO@@ -4,9 +4,6 @@ ql_build_rx_skb(). That function is now used exclusively to handle packets that underwent header splitting but it still contains code to handle non split cases. -* the flow control implementation in firmware is buggy (sends a flood of pause - frames, resets the link, device and driver buffer queues become - desynchronized), disable it by default * some structures are initialized redundantly (ex. memset 0 after alloc_etherdev()) * the driver has a habit of using runtime checks where compile time checks arediff --git a/drivers/staging/qlge/qlge_mpi.c b/drivers/staging/qlge/qlge_mpi.c index 2630ebf50341..0f1c7da80413 100644 --- a/drivers/staging/qlge/qlge_mpi.c +++ b/drivers/staging/qlge/qlge_mpi.c@@ -806,6 +806,7 @@ int qlge_mb_get_port_cfg(struct qlge_adapter *qdev) { struct mbox_params mbc; struct mbox_params *mbcp = &mbc; + u32 saved_pause_link_config = 0;
Initialization is not needed given the code below, in fact the declaration can be moved to the block below.
quoted hunk ↗ jump to hunk
int status = 0; memset(mbcp, 0, sizeof(struct mbox_params));@@ -826,7 +827,15 @@ int qlge_mb_get_port_cfg(struct qlge_adapter *qdev) } else { netif_printk(qdev, drv, KERN_DEBUG, qdev->ndev, "Passed Get Port Configuration.\n"); - qdev->link_config = mbcp->mbox_out[1]; + /* + * Don't let the pause parameter be overwritten by + * + * In this way, follow control can be disabled by default + * and the setting could also survive the MPI reset + */
It seems this comment is incomplete. Also, it's "flow control", not "follow control".
+ saved_pause_link_config = qdev->link_config & CFG_PAUSE_STD; + qdev->link_config = ~CFG_PAUSE_STD & mbcp->mbox_out[1]; + qdev->link_config |= saved_pause_link_config; qdev->max_frame_size = mbcp->mbox_out[2]; } return status; -- 2.32.0