From: White Ding Date: Wed, 23 Jul 2014 16:10:45 +0000 (+0800) Subject: mtd: nand: fix nand_lock/unlock() function X-Git-Tag: fixes-against-v3.18-rc2~54^2~33^2~17 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=57d3a9a89a0645f3597561e214f8d6852a2c56b4;p=pandora-kernel.git mtd: nand: fix nand_lock/unlock() function Do nand reset before write protect check. If we want to check the WP# low or high through STATUS READ and check bit 7, we must reset the device, other operation (eg.erase/program a locked block) can also clear the bit 7 of status register. As we know the status register can be refreshed, if we do some operation to trigger it, for example if we do erase/program operation to one block that is locked, then READ STATUS, the bit 7 of READ STATUS will be 0 indicate the device in write protect, then if we do erase/program operation to another block that is unlocked, the bit 7 of READ STATUS will be 1 indicate the device is not write protect. Suppose we checked the bit 7 of READ STATUS is 0 then judge the WP# is low (write protect), but in this case the WP# maybe high if we do erase/program operation to a locked block, so we must reset the device if we want to check the WP# low or high through STATUS READ and check bit 7. Signed-off-by: White Ding Signed-off-by: Brian Norris --- Reading git-diff-tree failed