[U-Boot] [PATCH] mmc:sdhci:fix: Change default interrupts enabled at SDHCI initialization

From: Jaehoon Chung <jh80.chung@samsung.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] mmc:sdhci:fix: Change default interrupts enabled at SDHCI initialization
Date: Fri, 22 Feb 2013 08:33:34 +0900	[thread overview]
Message-ID: <5126AECE.2020509@samsung.com> (raw)
In-Reply-To: <51265D33.8030606@ti.com>

Hi Tom,

On 02/22/2013 02:45 AM, Tom Rini wrote:
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> On 02/21/2013 12:21 PM, Lukasz Majewski wrote:
>> Dear All,
>>
>> I'd like to kindly ask for any feedback on this patch.
>>
>> It is now more than month on the u-boot mailing list...
> 
> OK, sorry, the generic name of the driver threw me for a minute.  I'm
> fine with this change going up u-boot-samsung -> u-boot-arm -> master
> since it's a samsung-only driver right now.  Does this work for you?
I think that this driver didn't use samsung-only.
going up u-boot-samsung? I'm not sure that.

Best Regards,
Jaehoon Chung
> 
>>
>>
>>> Dear All,
>>>
>>> Any feedback about this patch?
>>>
>>> It has been on the list for quite long time.....
>>>
>>>
>>>> Dear All,
>>>>
>>>> Any feedback about this patch?
>>>>
>>>>> This patch changes sdhci_init()'s behavior to NOT enable all 
>>>>> interrupt sources by default. Moreover interrupt signaling
>>>>> has been disabled.
>>>>>
>>>>> This patch do not enable interrupts which aren't served in
>>>>> u-boot (they are defined at sdhci.h but NOT used elsewhere): 
>>>>> - SDHCI_INT_CARD_INSERT, SDHCI_INT_CARD_REMOVE,
>>>>> SDHCI_BUS_POWER, SDHCI_INT_CARD_REMOVE, SDHCI_INT_CARD_INT
>>>>>
>>>>> Special care shall be put on SDHCI_INT_CARD_INT, which
>>>>> indicates interrupt generated by SD card. According to "SD
>>>>> Host Controller Simplified Spec. ver 3.00" when bit 8 (Card
>>>>> Interrupt Status Enable) at "Normal Interrupt Status Enable
>>>>> Register" (offset 0x34) is set, the card interrupt detection
>>>>> is started. Then eMMC card may cause the SD controller to set
>>>>> this bit and then this interrupt is passed to booted OS and
>>>>> might cause kernel crash.
>>>>>
>>>>>
>>>>> To sum up: - Only enable interrupts, which are served at
>>>>> u-boot - This cleanup as a side effect fixes SDHCI's CARD
>>>>> INTERRUPT problem at Linux kernel (versions 3.6+, sdhci
>>>>> controller) - Keep masked bits at "Normal Interrupt Signal
>>>>> Enable Register" (0x38h)
>>>>>
>>>>> Signed-off-by: Lukasz Majewski <l.majewski@samsung.com> 
>>>>> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Cc:
>>>>> Lei Wen <leiwen@marvell.com> Cc: Andy Fleming
>>>>> <afleming@freescale.com> --- drivers/mmc/sdhci.c |    8
>>>>> +++++--- 1 files changed, 5 insertions(+), 3 deletions(-)
>>>>>
>>>>> diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c index
>>>>> 0fd1337..76c14fb 100644 --- a/drivers/mmc/sdhci.c +++
>>>>> b/drivers/mmc/sdhci.c @@ -412,9 +412,11 @@ int
>>>>> sdhci_init(struct mmc *mmc) status = sdhci_readl(host, 
>>>>> SDHCI_PRESENT_STATE); }
>>>>>
>>>>> -	/* Eable all state */ -	sdhci_writel(host,
>>>>> SDHCI_INT_ALL_MASK, SDHCI_INT_ENABLE); -	sdhci_writel(host,
>>>>> SDHCI_INT_ALL_MASK, SDHCI_SIGNAL_ENABLE); +	/* Enable only
>>>>> interrupts served by the SD controller */ +
>>>>> sdhci_writel(host, SDHCI_INT_DATA_MASK | SDHCI_INT_CMD_MASK +
>>>>> , SDHCI_INT_ENABLE); +	/* Mask all sdhci interrupt sources
>>>>> */ +	sdhci_writel(host, 0x0, SDHCI_SIGNAL_ENABLE);
>>>>>
>>>>> return 0; }
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>
> 
> 
> - -- 
> Tom
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