RE: 1217:8520 [Dell Latitude E7450] O2 Micro, SD/MMC Card Reader doesn't work

[Peter Guo <peter.guo@bayhubtech.com>]

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Hi Alex & Adam,

I have send the patch. Please check it.
Attachment is the patch file.


BR
Peter.Guo

-----Original Message-----
From: Alex Ballas [mailto:alex@ballas.org] 
Sent: Wednesday, December 16, 2015 5:49 PM
To: Peter Guo; adam8157@gmail.com
Cc: ulf.hansson@linaro.org; linux-mmc@VGER.KERNEL.ORG
Subject: Re: 1217:8520 [Dell Latitude E7450] O2 Micro, SD/MMC Card Reader doesn't work

Re-adding Adam as the initial mail address is bouncing.

Kind Regards,
Alex


On Wed, Dec 16, 2015 at 5:42 AM, Peter Guo <peter.guo@bayhubtech.com> wrote:
> Hi Alex,
>
> Thanks for your Test, According to your info.
> I find the root cause of this issue is quirks 
> SDHCI_QUIRK2_CLEAR_TRANSFERMODE_REG_BEFORE_CMD is not suitable for our host for all cases.  Our host just want to clear SDHCI_TRANS_DMA bit only.
>
> to Adam,
>
> I will commit new patch this week, please check it.
>
>
> BR
> Peter.Guo
>
> -----Original Message-----
> From: Alex Ballas [mailto:alex@ballas.org]
> Sent: Saturday, December 12, 2015 10:04 PM
> To: Peter Guo; adam.lee@canonical.com; ulf.hansson@linaro.org
> Cc: linux-mmc@VGER.KERNEL.ORG
> Subject: 1217:8520 [Dell Latitude E7450] O2 Micro, SD/MMC Card Reader 
> doesn't work
>
> Hello,
>
> I have a Dell Latitude E7450 with a O2 Micro, SD/MMC Card Reader [1217:8520] card reader. When I insert my Sandisk ultra 64GB microSD (with a SD card adapter) I get the following errors.
>
> Dmesg output after I insert the SD card:
>
> [  306.054203] sdhci: Timeout waiting for Buffer Read Ready interrupt 
> during tuning procedure, falling back to fixed sampling clock [  
> 306.055982] mmc0: tuning execution failed [  306.055987] mmc0: error 
> -5 whilst initialising SD card [  306.466185] sdhci: Timeout waiting 
> for Buffer Read Ready interrupt during tuning procedure, falling back 
> to fixed sampling clock [  306.467964] mmc0: tuning execution failed [  
> 306.467970] mmc0: error -5 whilst initialising SD card [  306.890205] 
> sdhci: Timeout waiting for Buffer Read Ready interrupt during tuning 
> procedure, falling back to fixed sampling clock [  306.891993] mmc0: 
> tuning execution failed [  306.892005] mmc0: error -5 whilst 
> initialising SD card [  307.330197] sdhci: Timeout waiting for Buffer 
> Read Ready interrupt during tuning procedure, falling back to fixed 
> sampling clock [  307.331980] mmc0: tuning execution failed [  
> 307.331990] mmc0: error -5 whilst initialising SD card
>
> I used the latest mainline kernel available to me [1] $ uname -a Linux 
> cosmo 4.4.0-040400rc4-generic #201512061930 SMP Mon Dec 7
> 00:32:31 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
>
> It was working fine for kernel versions older than 4.1.8.
>
> I did a bisection and here is the first bad commit
>
>> e6c69099f63c84e1825c0f742a76ff4a8afeaa9b is the first bad commit 
>> commit e6c69099f63c84e1825c0f742a76ff4a8afeaa9b
>> Author: Adam Lee <adam.lee@canonical.com>
>> Date:   Mon Aug 3 14:33:28 2015 +0800
>>
>>     mmc: sdhci-pci: set the clear transfer mode register quirk for 
>> O2Micro
>>
>>     commit 143b648ddf1583905fa15d32be27a31442fc7933 upstream.
>>
>>     This patch fixes MMC not working issue on O2Micro/BayHub Host, which
>>     requires transfer mode register to be cleared when sending no DMA
>>     command.
>>
>>     Signed-off-by: Peter Guo <peter.guo@bayhubtech.com>
>>     Signed-off-by: Adam Lee <adam.lee@canonical.com>
>>     Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
>>     Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>
> I originally logged this issue to the Ubuntu bug tracker[2], but it appears to be an upstream issue and so I was instructed to report here.
> Please note that I use the latest Bios version for the model.
>
> $ sudo dmidecode -s bios-version;sudo dmidecode -s bios-release-date
> A08
> 10/28/2015
>
> [1] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.4-rc4-wily/
> [2] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1523178
>
> Thanks,
> Alex

[-- Attachment #2: 0001-mmc-sdhci-Add-QUIRK2_CLEAR_TRANSFERMODE_DMA_BEFORE_CMD.patch --]
[-- Type: application/octet-stream, Size: 2534 bytes --]

From b3862562928dfbc1fa971d2d092a6f0580294d4b Mon Sep 17 00:00:00 2001
From: "peter.guo" <peter.guo@bayhubtech.com>
Date: Fri, 18 Dec 2015 10:44:16 +0800
Subject: [PATCH 1/1] mmc: sdhci: Add QUIRK2_CLEAR_TRANSFERMODE_DMA_BEFORE_CMD for o2Micro chip

Add SDHCI_QUIRK2_CLEAR_TRANSFERMODE_DMA_BEFORE_CMD quirks2 for requires transfer
mode register SDHCI_TRNS_DMA bit to be cleared when sending no DMA.
Apply this quirks for O2Micro chip instead of SDHCI_QUIRK2_CLEAR_TRANSFERMODE_REG_BEFORE_CMD:
        a.  MMC card not working issue
        b.  SD tuning failed issue.

Signed-off-by: Peter Guo <peter.guo@bayhubtech.com>
---
 drivers/mmc/host/sdhci-pci-core.c | 2 +-
 drivers/mmc/host/sdhci.c          | 4 ++++
 drivers/mmc/host/sdhci.h          | 3 +++
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
index cf7ad45..3a6f179 100644
--- a/drivers/mmc/host/sdhci-pci-core.c
+++ b/drivers/mmc/host/sdhci-pci-core.c
@@ -614,7 +614,7 @@ static int jmicron_resume(struct sdhci_pci_chip *chip)
 static const struct sdhci_pci_fixes sdhci_o2 = {
 	.probe = sdhci_pci_o2_probe,
 	.quirks = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC,
-	.quirks2 = SDHCI_QUIRK2_CLEAR_TRANSFERMODE_REG_BEFORE_CMD,
+	.quirks2 = SDHCI_QUIRK2_CLEAR_TRANSFERMODE_DMA_BEFORE_CMD,
 	.probe_slot = sdhci_pci_o2_probe_slot,
 	.resume = sdhci_pci_o2_resume,
 };
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index b48565e..fba9260 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -902,6 +902,10 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
 		} else {
 		/* clear Auto CMD settings for no data CMDs */
 			mode = sdhci_readw(host, SDHCI_TRANSFER_MODE);
+			if (host->quirks2 &
+			    SDHCI_QUIRK2_CLEAR_TRANSFERMODE_DMA_BEFORE_CMD) {
+				mode &= ~(SDHCI_TRNS_DMA);
+			}
 			sdhci_writew(host, mode & ~(SDHCI_TRNS_AUTO_CMD12 |
 				SDHCI_TRNS_AUTO_CMD23), SDHCI_TRANSFER_MODE);
 		}
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 9d4aa31..97fd107 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -417,6 +417,9 @@ struct sdhci_host {
  * SD clock frequency or enabling back the internal clock.
  */
 #define SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST	(1<<16)
+/* need clear transfer mode register SDHCI_TRNS_DMA BIT before send cmd */
+#define SDHCI_QUIRK2_CLEAR_TRANSFERMODE_DMA_BEFORE_CMD	(1<<17)
+
 
 	int irq;		/* Device IRQ */
 	void __iomem *ioaddr;	/* Mapped address */
-- 
1.9.1