Commit 6cc834ba authored by Keith Busch's avatar Keith Busch
Browse files

nvme: avoid bogus CRTO values 

Some devices are reporting controller ready mode support, but return 0
for CRTO. These devices require a much higher time to ready than that,
so they are failing to initialize after the driver starter preferring
that value over CAP.TO.

The spec requires that CAP.TO match the appropritate CRTO value, or be
set to 0xff if CRTO is larger than that. This means that CAP.TO can be
used to validate if CRTO is reliable, and provides an appropriate
fallback for setting the timeout value if not. Use whichever is larger.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217863


Reported-by: default avatarCláudio Sampaio <patola@gmail.com>
Reported-by: default avatarFelix Yan <felixonmars@archlinux.org>
Tested-by: default avatarFelix Yan <felixonmars@archlinux.org>
Based-on-a-patch-by: default avatarFelix Yan <felixonmars@archlinux.org>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
parent dad651b2

drivers/nvme/host/core.c

+35 −19
Original line number Diff line number Diff line
@@ -2245,25 +2245,8 @@ int nvme_enable_ctrl(struct nvme_ctrl *ctrl) 
	else

		ctrl->ctrl_config = NVME_CC_CSS_NVM;



	if (ctrl->cap & NVME_CAP_CRMS_CRWMS) {

		u32 crto;



		ret = ctrl->ops->reg_read32(ctrl, NVME_REG_CRTO, &crto);

		if (ret) {

			dev_err(ctrl->device, "Reading CRTO failed (%d)\n",

				ret);

			return ret;

		}



		if (ctrl->cap & NVME_CAP_CRMS_CRIMS) {

	if (ctrl->cap & NVME_CAP_CRMS_CRWMS && ctrl->cap & NVME_CAP_CRMS_CRIMS)

		ctrl->ctrl_config |= NVME_CC_CRIME;

			timeout = NVME_CRTO_CRIMT(crto);

		} else {

			timeout = NVME_CRTO_CRWMT(crto);

		}

	} else {

		timeout = NVME_CAP_TIMEOUT(ctrl->cap);

	}



	ctrl->ctrl_config |= (NVME_CTRL_PAGE_SHIFT - 12) << NVME_CC_MPS_SHIFT;

	ctrl->ctrl_config |= NVME_CC_AMS_RR | NVME_CC_SHN_NONE;
@@ -2277,6 +2260,39 @@ int nvme_enable_ctrl(struct nvme_ctrl *ctrl) 
	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)

		return ret;



	timeout = NVME_CAP_TIMEOUT(ctrl->cap);

	if (ctrl->cap & NVME_CAP_CRMS_CRWMS) {

		u32 crto, ready_timeout;



		ret = ctrl->ops->reg_read32(ctrl, NVME_REG_CRTO, &crto);

		if (ret) {

			dev_err(ctrl->device, "Reading CRTO failed (%d)\n",

				ret);

			return ret;

		}



		/*

		 * CRTO should always be greater or equal to CAP.TO, but some

		 * devices are known to get this wrong. Use the larger of the

		 * two values.

		 */

		if (ctrl->ctrl_config & NVME_CC_CRIME)

			ready_timeout = NVME_CRTO_CRIMT(crto);

		else

			ready_timeout = NVME_CRTO_CRWMT(crto);



		if (ready_timeout < timeout)

			dev_warn_once(ctrl->device, "bad crto:%x cap:%llx\n",

				      crto, ctrl->cap);

		else

			timeout = ready_timeout;

	}



	ctrl->ctrl_config |= NVME_CC_ENABLE;

	ret = ctrl->ops->reg_write32(ctrl, NVME_REG_CC, ctrl->ctrl_config);

	if (ret)