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Commit 9a12f57a authored by Tanya Brokhman's avatar Tanya Brokhman
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Revert "mtd: ubi: Add kconfig to handle RD at attach" 



This reverts commit 47edb451.

This patch is part of the "read-disturb implementation" set of patches.
It was decided to take different approach in addressing the read disturb,
thus the whole patch series is reverted in order to simplify the code
and reduce memory footprint.

Change-Id: I598f27892f0fddf4159393b28c4446b4abf329e5
Signed-off-by: default avatarTanya Brokhman <tlinder@codeaurora.org>
parent dfc13902

drivers/mtd/ubi/Kconfig

+0 −13
Original line number Original line Diff line number Diff line
@@ -77,19 +77,6 @@ config MTD_UBI_FASTMAP 




	   If in doubt, say "N".

	   If in doubt, say "N".





config MTD_UBI_ENABLE_RD_AT_ATTACH

	bool "UBI handle read disturb at attach. (Experimental feature)"

	help

	   Important: this feature is experimental so far and may be removed

	   entirely in the future.



	   Handle the read disturb errors that can happen in NAND devices

	   by checking the last erased timestamp and the read count of the

	   PEB's at attach time in addition to runtime. This can cause

	   significant overhead during attach and must be used with caution.



	   If in doubt, say "N".



config MTD_UBI_GLUEBI

config MTD_UBI_GLUEBI

	tristate "MTD devices emulation driver (gluebi)"

	tristate "MTD devices emulation driver (gluebi)"

	help

	help

drivers/mtd/ubi/wl.c

+5 −31
Original line number Original line Diff line number Diff line
@@ -2090,21 +2090,6 @@ static void cancel_pending(struct ubi_device *ubi) 
	}

	}

}

}





/**

 * enable_check_rd_at_attach - Enable the check read disturb at attach.

 */

#ifdef CONFIG_MTD_UBI_ENABLE_RD_AT_ATTACH

static bool enable_check_rd_at_attach(void)

{

	return true;

}

#else

static bool enable_check_rd_at_attach(void)

{

	return false;

}

#endif



/**

/**

 * ubi_wl_init - initialize the WL sub-system using attaching information.

 * ubi_wl_init - initialize the WL sub-system using attaching information.

 * @ubi: UBI device description object

 * @ubi: UBI device description object
@@ -2121,13 +2106,6 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai) 
	struct ubi_ainf_peb *aeb, *tmp;

	struct ubi_ainf_peb *aeb, *tmp;

	struct ubi_wl_entry *e;

	struct ubi_wl_entry *e;

	struct timeval tv;

	struct timeval tv;

	bool check_rd_at_attach;



	check_rd_at_attach = enable_check_rd_at_attach();

	if (check_rd_at_attach)

		ubi_msg(ubi->ubi_num, "Read disturb check ENABLED at attach");

	else

		ubi_msg(ubi->ubi_num, "Read disturb check DISABLED at attach");





	do_gettimeofday(&tv);

	do_gettimeofday(&tv);

	ubi->used = ubi->erroneous = ubi->free = ubi->scrub = RB_ROOT;

	ubi->used = ubi->erroneous = ubi->free = ubi->scrub = RB_ROOT;
@@ -2214,11 +2192,9 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai) 
		ubi_assert(e->ec >= 0);

		ubi_assert(e->ec >= 0);

		ubi_assert(!ubi_is_fm_block(ubi, e->pnum));

		ubi_assert(!ubi_is_fm_block(ubi, e->pnum));

		ubi->lookuptbl[e->pnum] = e;

		ubi->lookuptbl[e->pnum] = e;



		/* Check last erase timestamp (in days) */

		/* Check last erase timestamp (in days) */

		if (check_rd_at_attach &&

		if (e->last_erase_time + ubi->dt_threshold <

			(e->last_erase_time + ubi->dt_threshold <

			(tv.tv_sec / NUM_SEC_IN_DAY)) {

			(tv.tv_sec / NUM_SEC_IN_DAY))) {

			if (schedule_erase(ubi, e, aeb->vol_id, aeb->lnum, 0)) {

			if (schedule_erase(ubi, e, aeb->vol_id, aeb->lnum, 0)) {

				kmem_cache_free(ubi_wl_entry_slab, e);

				kmem_cache_free(ubi_wl_entry_slab, e);

				goto out_free;

				goto out_free;
@@ -2262,16 +2238,14 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai) 
			 * Verify last erase timestamp

			 * Verify last erase timestamp

			 * (in days) and read counter

			 * (in days) and read counter

			 */

			 */

			if (check_rd_at_attach &&

			if (e->last_erase_time + ubi->dt_threshold <

				(e->last_erase_time + ubi->dt_threshold <

				(tv.tv_sec / NUM_SEC_IN_DAY) ||

				(tv.tv_sec / NUM_SEC_IN_DAY) ||

				e->rc > ubi->rd_threshold)) {

				e->rc > ubi->rd_threshold) {

				ubi_msg(ubi->ubi_num,

				ubi_msg(ubi->ubi_num,

					"scrub PEB %d rc = %d",

					"scrub PEB %d rc = %d",

				       e->pnum, e->rc);

				       e->pnum, e->rc);

				aeb->scrub = 1;

				aeb->scrub = 1;

			}

			}



			if (!aeb->scrub) {

			if (!aeb->scrub) {

				dbg_wl("add PEB %d EC %d to the used tree",

				dbg_wl("add PEB %d EC %d to the used tree",

				       e->pnum, e->ec);

				       e->pnum, e->ec);