Kernel/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-01-18 02:46:06 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

nvme: remove CC register read-back during enabling

Browse Source 
Any non-posted read should flush the previous write, so we don't
necessarily need to read back the value we just wrote. I've found at
least some controllers that respond with 0 for short moments after
writing the CC register with EN (enable) cleared, so the read-back is
overwriting our valid ctrl_config value and ends up breaking on the
subsequent enabling.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
This commit is contained in:
Keith Busch 2024-09-04 14:48:50 -07:00
parent 83340d9c61
commit 9064610348
1 changed files with 0 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/nvme/host/core.c
View File

@ -2468,11 +2468,6 @@ int nvme_enable_ctrl(struct nvme_ctrl *ctrl)
if (ret)
return ret;
/* Flush write to device (required if transport is PCI) */
ret = ctrl->ops->reg_read32(ctrl, NVME_REG_CC, &ctrl->ctrl_config);
if (ret)
return ret;
/* CAP value may change after initial CC write */
ret = ctrl->ops->reg_read64(ctrl, NVME_REG_CAP, &ctrl->cap);
if (ret)