Commit 26501db8 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Jens Axboe
Browse files

nvme/scsi: Remove power management support 



As far as I can tell, there is basically nothing correct about this
code.  It misinterprets npss (off-by-one).  It hardcodes a bunch of
power states, which is nonsense, because they're all just indices
into a table that software needs to parse.  It completely ignores
the distinction between operational and non-operational states.
And, until 4.8, if all of the above magically succeeded, it would
dereference a NULL pointer and OOPS.

Since this code appears to be useless, just delete it.

Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarJay Freyensee <james_p_freyensee@linux.intel.com>
Tested-by: default avatarJay Freyensee <james_p_freyensee@linux.intel.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 2e5d0baa

drivers/nvme/host/scsi.c

+3 −71
Original line number Diff line number Diff line
@@ -72,15 +72,6 @@ static int sg_version_num = 30534; /* 2 digits for each component */ 
#define ALL_LUNS_RETURNED				0x02

#define ALL_WELL_KNOWN_LUNS_RETURNED			0x01

#define RESTRICTED_LUNS_RETURNED			0x00

#define NVME_POWER_STATE_START_VALID			0x00

#define NVME_POWER_STATE_ACTIVE				0x01

#define NVME_POWER_STATE_IDLE				0x02

#define NVME_POWER_STATE_STANDBY			0x03

#define NVME_POWER_STATE_LU_CONTROL			0x07

#define POWER_STATE_0					0

#define POWER_STATE_1					1

#define POWER_STATE_2					2

#define POWER_STATE_3					3

#define DOWNLOAD_SAVE_ACTIVATE				0x05

#define DOWNLOAD_SAVE_DEFER_ACTIVATE			0x0E

#define ACTIVATE_DEFERRED_MICROCODE			0x0F
@@ -1229,64 +1220,6 @@ static void nvme_trans_fill_read_cap(u8 *response, struct nvme_id_ns *id_ns, 


/* Start Stop Unit Helper Functions */



static int nvme_trans_power_state(struct nvme_ns *ns, struct sg_io_hdr *hdr,

						u8 pc, u8 pcmod, u8 start)

{

	int res;

	int nvme_sc;

	struct nvme_id_ctrl *id_ctrl;

	int lowest_pow_st;	/* max npss = lowest power consumption */

	unsigned ps_desired = 0;



	nvme_sc = nvme_identify_ctrl(ns->ctrl, &id_ctrl);

	res = nvme_trans_status_code(hdr, nvme_sc);

	if (res)

		return res;



	lowest_pow_st = max(POWER_STATE_0, (int)(id_ctrl->npss - 1));

	kfree(id_ctrl);



	switch (pc) {

	case NVME_POWER_STATE_START_VALID:

		/* Action unspecified if POWER CONDITION MODIFIER != 0 */

		if (pcmod == 0 && start == 0x1)

			ps_desired = POWER_STATE_0;

		if (pcmod == 0 && start == 0x0)

			ps_desired = lowest_pow_st;

		break;

	case NVME_POWER_STATE_ACTIVE:

		/* Action unspecified if POWER CONDITION MODIFIER != 0 */

		if (pcmod == 0)

			ps_desired = POWER_STATE_0;

		break;

	case NVME_POWER_STATE_IDLE:

		/* Action unspecified if POWER CONDITION MODIFIER != [0,1,2] */

		if (pcmod == 0x0)

			ps_desired = POWER_STATE_1;

		else if (pcmod == 0x1)

			ps_desired = POWER_STATE_2;

		else if (pcmod == 0x2)

			ps_desired = POWER_STATE_3;

		break;

	case NVME_POWER_STATE_STANDBY:

		/* Action unspecified if POWER CONDITION MODIFIER != [0,1] */

		if (pcmod == 0x0)

			ps_desired = max(POWER_STATE_0, (lowest_pow_st - 2));

		else if (pcmod == 0x1)

			ps_desired = max(POWER_STATE_0, (lowest_pow_st - 1));

		break;

	case NVME_POWER_STATE_LU_CONTROL:

	default:

		res = nvme_trans_completion(hdr, SAM_STAT_CHECK_CONDITION,

				ILLEGAL_REQUEST, SCSI_ASC_INVALID_CDB,

				SCSI_ASCQ_CAUSE_NOT_REPORTABLE);

		break;

	}

	nvme_sc = nvme_set_features(ns->ctrl, NVME_FEAT_POWER_MGMT, ps_desired, 0,

				    NULL);

	return nvme_trans_status_code(hdr, nvme_sc);

}



static int nvme_trans_send_activate_fw_cmd(struct nvme_ns *ns, struct sg_io_hdr *hdr,

					u8 buffer_id)

{
@@ -2235,11 +2168,10 @@ static int nvme_trans_synchronize_cache(struct nvme_ns *ns, 
static int nvme_trans_start_stop(struct nvme_ns *ns, struct sg_io_hdr *hdr,

							u8 *cmd)

{

	u8 immed, pcmod, pc, no_flush, start;

	u8 immed, pcmod, no_flush, start;



	immed = cmd[1] & 0x01;

	pcmod = cmd[3] & 0x0f;

	pc = (cmd[4] & 0xf0) >> 4;

	no_flush = cmd[4] & 0x04;

	start = cmd[4] & 0x01;
@@ -2254,8 +2186,8 @@ static int nvme_trans_start_stop(struct nvme_ns *ns, struct sg_io_hdr *hdr, 
			if (res)

				return res;

		}

		/* Setup the expected power state transition */

		return nvme_trans_power_state(ns, hdr, pc, pcmod, start);



		return 0;

	}

}

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