[PATCH] mmc: sdhci-esdhc-imx: correct the fix of ERR004536

[BOUGH CHEN <haibo.chen@nxp.com>]

Commit 18094430d6b5 ("mmc: sdhci-esdhc-imx: add ADMA Length
Mismatch errata fix") involve the fix of ERR004536, but the
fix is incorrect. Double confirm with IC, need to clear the
bit 7 of register 0x6c rather than set this bit 7.
Here is the definition of bit 7 of 0x6c:
    0: enable the new IC fix for ERR004536
    1: do not use the IC fix, keep the same as before

Due to the reset value of this bit 7 is 0, ROM code and
bootloader do not touch this bit 7, so here directly remove
the operation of this bit 7, make sure the fix of ERR004536
can work.

Find this issue on i.MX845s-evk board when enable CMDQ, and
let system in heavy loading.

root@imx8mmevk:~# dd if=/dev/mmcblk2 of=/dev/null bs=1M &
root@imx8mmevk:~# memtester 1000M > /dev/zero &
root@imx8mmevk:~# [  139.897220] mmc2: cqhci: timeout for tag 16
[  139.901417] mmc2: cqhci: ============ CQHCI REGISTER DUMP ===========
[  139.907862] mmc2: cqhci: Caps:      0x0000310a | Version:  0x00000510
[  139.914311] mmc2: cqhci: Config:    0x00001001 | Control:  0x00000000
[  139.920753] mmc2: cqhci: Int stat:  0x00000000 | Int enab: 0x00000006
[  139.927193] mmc2: cqhci: Int sig:   0x00000006 | Int Coal: 0x00000000
[  139.933634] mmc2: cqhci: TDL base:  0x7809c000 | TDL up32: 0x00000000
[  139.940073] mmc2: cqhci: Doorbell:  0x00030000 | TCN:      0x00000000
[  139.946518] mmc2: cqhci: Dev queue: 0x00010000 | Dev Pend: 0x00010000
[  139.952967] mmc2: cqhci: Task clr:  0x00000000 | SSC1:     0x00011000
[  139.959411] mmc2: cqhci: SSC2:      0x00000001 | DCMD rsp: 0x00000000
[  139.965857] mmc2: cqhci: RED mask:  0xfdf9a080 | TERRI:    0x00000000
[  139.972308] mmc2: cqhci: Resp idx:  0x0000002e | Resp arg: 0x00000900
[  139.978761] mmc2: sdhci: ============ SDHCI REGISTER DUMP ===========
[  139.985214] mmc2: sdhci: Sys addr:  0xb2c19000 | Version:  0x00000002
[  139.991669] mmc2: sdhci: Blk size:  0x00000200 | Blk cnt:  0x00000400
[  139.998127] mmc2: sdhci: Argument:  0x40110400 | Trn mode: 0x00000033
[  140.004618] mmc2: sdhci: Present:   0x01088a8f | Host ctl: 0x00000030
[  140.011113] mmc2: sdhci: Power:     0x00000002 | Blk gap:  0x00000080
[  140.017583] mmc2: sdhci: Wake-up:   0x00000008 | Clock:    0x0000000f
[  140.024039] mmc2: sdhci: Timeout:   0x0000008f | Int stat: 0x00000000
[  140.030497] mmc2: sdhci: Int enab:  0x107f4000 | Sig enab: 0x107f4000
[  140.036972] mmc2: sdhci: AC12 err:  0x00000000 | Slot int: 0x00000502
[  140.043426] mmc2: sdhci: Caps:      0x07eb0000 | Caps_1:   0x8000b407
[  140.049867] mmc2: sdhci: Cmd:       0x00002c1a | Max curr: 0x00ffffff
[  140.056314] mmc2: sdhci: Resp[0]:   0x00000900 | Resp[1]:  0xffffffff
[  140.062755] mmc2: sdhci: Resp[2]:   0x328f5903 | Resp[3]:  0x00d00f00
[  140.069195] mmc2: sdhci: Host ctl2: 0x00000008
[  140.073640] mmc2: sdhci: ADMA Err:  0x00000007 | ADMA Ptr: 0x7809c108
[  140.080079] mmc2: sdhci: ============================================
[  140.086662] mmc2: running CQE recovery

Fixes commit 18094430d6b5 ("mmc: sdhci-esdhc-imx: add ADMA Length Mismatch errata fix")
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Cc: stable@vger.kernel.org
---
 drivers/mmc/host/sdhci-esdhc-imx.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 32ca3703b432..5ee7613c818f 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -1171,12 +1171,6 @@ static void sdhci_esdhc_imx_hwinit(struct sdhci_host *host)
 		writel(readl(host->ioaddr + SDHCI_HOST_CONTROL)
 			| ESDHC_BURST_LEN_EN_INCR,
 			host->ioaddr + SDHCI_HOST_CONTROL);
-		/*
-		* erratum ESDHC_FLAG_ERR004536 fix for MX6Q TO1.2 and MX6DL
-		* TO1.1, it's harmless for MX6SL
-		*/
-		writel(readl(host->ioaddr + 0x6c) | BIT(7),
-			host->ioaddr + 0x6c);
 
 		/* disable DLL_CTRL delay line settings */
 		writel(0x0, host->ioaddr + ESDHC_DLL_CTRL);
-- 
2.17.1