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authorJohn Crispin <john@phrozen.org>2016-06-21 00:32:11 +0300
committerBoris Brezillon <boris.brezillon@free-electrons.com>2016-07-11 09:40:15 +0300
commite7e1f7be335458139e0a112bd0aae40d33dfe3a8 (patch)
tree7f18bc7c7077ada41cf0848683543fbd7e621dff /drivers/mtd
parent44772fa5ec4162ef133f1294299d1e1ada7d2d11 (diff)
downloadlinux-e7e1f7be335458139e0a112bd0aae40d33dfe3a8.tar.xz
mtd: nand: xway: fix nand locking
The external Bus Unit (EBU) can control different flash devices, but these NAND flash commands have to be atomic and should not be interrupted in between. Lock the EBU from the beginning of the command till the end by moving the lock to the chip select. Signed-off-by: John Crispin <john@phrozen.org> Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/nand/xway_nand.c20
1 files changed, 8 insertions, 12 deletions
diff --git a/drivers/mtd/nand/xway_nand.c b/drivers/mtd/nand/xway_nand.c
index ab93b3536877..08f796eaa624 100644
--- a/drivers/mtd/nand/xway_nand.c
+++ b/drivers/mtd/nand/xway_nand.c
@@ -65,17 +65,22 @@
struct xway_nand_data {
struct nand_chip chip;
+ unsigned long csflags;
};
-static void xway_select_chip(struct mtd_info *mtd, int chip)
+static void xway_select_chip(struct mtd_info *mtd, int select)
{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct xway_nand_data *data = nand_get_controller_data(chip);
- switch (chip) {
+ switch (select) {
case -1:
ltq_ebu_w32_mask(NAND_CON_CE, 0, EBU_NAND_CON);
ltq_ebu_w32_mask(NAND_CON_NANDM, 0, EBU_NAND_CON);
+ spin_unlock_irqrestore(&ebu_lock, data->csflags);
break;
case 0:
+ spin_lock_irqsave(&ebu_lock, data->csflags);
ltq_ebu_w32_mask(0, NAND_CON_NANDM, EBU_NAND_CON);
ltq_ebu_w32_mask(0, NAND_CON_CE, EBU_NAND_CON);
break;
@@ -88,12 +93,10 @@ static void xway_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
struct nand_chip *this = mtd_to_nand(mtd);
unsigned long nandaddr = (unsigned long) this->IO_ADDR_W;
- unsigned long flags;
if (cmd == NAND_CMD_NONE)
return;
- spin_lock_irqsave(&ebu_lock, flags);
if (ctrl & NAND_CLE)
writeb(cmd, (void __iomem *) (nandaddr | NAND_WRITE_CMD));
else if (ctrl & NAND_ALE)
@@ -101,7 +104,6 @@ static void xway_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
;
- spin_unlock_irqrestore(&ebu_lock, flags);
}
static int xway_dev_ready(struct mtd_info *mtd)
@@ -113,14 +115,8 @@ static unsigned char xway_read_byte(struct mtd_info *mtd)
{
struct nand_chip *this = mtd_to_nand(mtd);
unsigned long nandaddr = (unsigned long) this->IO_ADDR_R;
- unsigned long flags;
- int ret;
- spin_lock_irqsave(&ebu_lock, flags);
- ret = ltq_r8((void __iomem *)(nandaddr + NAND_READ_DATA));
- spin_unlock_irqrestore(&ebu_lock, flags);
-
- return ret;
+ return ltq_r8((void __iomem *)(nandaddr + NAND_READ_DATA));
}
/*