github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-27 16:44:58 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

qed: allow the callee of qed_mcp_nvm_read() to sleep

Browse Source 
qed_mcp_nvm_read has a loop where it calls qed_mcp_nvm_rd_cmd with the
argument b_can_sleep=false. And it sleeps once every 0x1000 bytes
read.

Simplify this by letting qed_mcp_nvm_rd_cmd itself sleep
(b_can_sleep=true). It will have slept at least once when successful
(in the "Wait for the MFW response" loop). So the extra sleep once every
0x1000 bytes becomes superfluous. Delete it.

On my test system with voluntary preemption, this lowers the latency
caused by 'ethtool -d' from 53 ms to 10 ms.

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Link: https://patch.msgid.link/20240930201307.330692-4-mschmidt@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Michal Schmidt 2024-09-30 22:13:06 +02:00 committed by Jakub Kicinski
parent 6cd695706f
commit cf54ae6b59
1 changed files with 1 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
drivers/net/ethernet/qlogic/qed/qed_mcp.c
View File

@ -3079,20 +3079,13 @@ int qed_mcp_nvm_read(struct qed_dev *cdev, u32 addr, u8 *p_buf, u32 len)
DRV_MB_PARAM_NVM_LEN_OFFSET),
&resp, &resp_param,
&read_len,
(u32 *)(p_buf + offset), false);
(u32 *)(p_buf + offset), true);
if (rc || (resp != FW_MSG_CODE_NVM_OK)) {
DP_NOTICE(cdev, "MCP command rc = %d\n", rc);
break;
}
/* This can be a lengthy process, and it's possible scheduler
* isn't preemptible. Sleep a bit to prevent CPU hogging.
*/
if (bytes_left % 0x1000 <
(bytes_left - read_len) % 0x1000)
usleep_range(1000, 2000);
offset += read_len;
bytes_left -= read_len;
}