mmc: sdhci-esdhc-imx: correct the fix of ERR004536

commit e30be063 upstream.

Commit 18094430 ("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

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: 18094430 ("mmc: sdhci-esdhc-imx: add ADMA Length Mismatch errata fix")
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/mmc/host/sdhci-esdhc-imx.c

@@ -1097,11 +1097,12 @@ 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),
+		 * 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 */