* [PATCH 2/5] mmc: dw-mmc: ensure that the card is not busy when changing clock.
@ 2012-08-23 11:31 Jaehoon Chung
2012-08-23 12:33 ` Will Newton
2012-08-24 3:55 ` Seungwon Jeon
0 siblings, 2 replies; 7+ messages in thread
From: Jaehoon Chung @ 2012-08-23 11:31 UTC (permalink / raw)
To: linux-mmc; +Cc: Chris Ball, Kyungmin Park, Will Newton, James Hogan
To avoid glitches in the card clock output,
need to check whether card is busy or not.
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
drivers/mmc/host/dw_mmc.c | 30 ++++++++++++++++++++++++------
drivers/mmc/host/dw_mmc.h | 1 +
2 files changed, 25 insertions(+), 6 deletions(-)
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 36f98c0..8bef3c2 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -623,6 +623,27 @@ static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
cmd, arg, cmd_status);
}
+static void dw_mci_inform_ciu(struct dw_mci_slot *slot)
+{
+ struct dw_mci *host = slot->host;
+ unsigned long timeout = jiffies + msecs_to_jiffies(500);
+ u32 ctrl, status;
+
+ do {
+ status = mci_readl(host, STATUS);
+ if (!(status & SDMMC_DATA_BUSY))
+ break;
+ ctrl = mci_readl(host, CTRL);
+ ctrl |= SDMMC_CTRL_RESET;
+ mci_writel(host, CTRL, ctrl);
+ } while (time_before(jiffies, timeout));
+
+ if (status & SDMMC_DATA_BUSY)
+ dev_err(&slot->mmc->class_dev,"Card is busy..!\n");
+
+ mci_send_cmd(slot, SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
+}
+
static void dw_mci_setup_bus(struct dw_mci_slot *slot)
{
struct dw_mci *host = slot->host;
@@ -650,15 +671,13 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
mci_writel(host, CLKSRC, 0);
/* inform CIU */
- mci_send_cmd(slot,
- SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
+ dw_mci_inform_ciu(slot);
/* set clock to desired speed */
mci_writel(host, CLKDIV, div);
/* inform CIU */
- mci_send_cmd(slot,
- SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
+ dw_mci_inform_ciu(slot);
/* enable clock; only low power if no SDIO */
clk_en_a = SDMMC_CLKEN_ENABLE << slot->id;
@@ -667,8 +686,7 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
mci_writel(host, CLKENA, clk_en_a);
/* inform CIU */
- mci_send_cmd(slot,
- SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
+ dw_mci_inform_ciu(slot);
host->current_speed = slot->clock;
}
diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
index 15c27e1..b6a1a78 100644
--- a/drivers/mmc/host/dw_mmc.h
+++ b/drivers/mmc/host/dw_mmc.h
@@ -127,6 +127,7 @@
#define SDMMC_CMD_INDX(n) ((n) & 0x1F)
/* Status register defines */
#define SDMMC_GET_FCNT(x) (((x)>>17) & 0x1FFF)
+#define SDMMC_DATA_BUSY BIT(9)
/* Internal DMAC interrupt defines */
#define SDMMC_IDMAC_INT_AI BIT(9)
#define SDMMC_IDMAC_INT_NI BIT(8)
--
1.7.4.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH 2/5] mmc: dw-mmc: ensure that the card is not busy when changing clock.
2012-08-23 11:31 [PATCH 2/5] mmc: dw-mmc: ensure that the card is not busy when changing clock Jaehoon Chung
@ 2012-08-23 12:33 ` Will Newton
2012-08-23 13:26 ` Jaehoon Chung
2012-08-24 3:55 ` Seungwon Jeon
1 sibling, 1 reply; 7+ messages in thread
From: Will Newton @ 2012-08-23 12:33 UTC (permalink / raw)
To: Jaehoon Chung
Cc: linux-mmc, Chris Ball, Kyungmin Park, Will Newton, James Hogan
On Thu, Aug 23, 2012 at 12:31 PM, Jaehoon Chung <jh80.chung@samsung.com> wrote:
> To avoid glitches in the card clock output,
> need to check whether card is busy or not.
>
> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> ---
> drivers/mmc/host/dw_mmc.c | 30 ++++++++++++++++++++++++------
> drivers/mmc/host/dw_mmc.h | 1 +
> 2 files changed, 25 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 36f98c0..8bef3c2 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -623,6 +623,27 @@ static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
> cmd, arg, cmd_status);
> }
>
> +static void dw_mci_inform_ciu(struct dw_mci_slot *slot)
> +{
> + struct dw_mci *host = slot->host;
> + unsigned long timeout = jiffies + msecs_to_jiffies(500);
Is there a reason why this timeout value was chosen? It seems quite long.
> + u32 ctrl, status;
> +
> + do {
> + status = mci_readl(host, STATUS);
> + if (!(status & SDMMC_DATA_BUSY))
> + break;
> + ctrl = mci_readl(host, CTRL);
> + ctrl |= SDMMC_CTRL_RESET;
> + mci_writel(host, CTRL, ctrl);
> + } while (time_before(jiffies, timeout));
> +
> + if (status & SDMMC_DATA_BUSY)
> + dev_err(&slot->mmc->class_dev,"Card is busy..!\n");
The two periods in this message do not need to be there.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 2/5] mmc: dw-mmc: ensure that the card is not busy when changing clock.
2012-08-23 12:33 ` Will Newton
@ 2012-08-23 13:26 ` Jaehoon Chung
0 siblings, 0 replies; 7+ messages in thread
From: Jaehoon Chung @ 2012-08-23 13:26 UTC (permalink / raw)
To: Will Newton
Cc: Jaehoon Chung, linux-mmc, Chris Ball, Kyungmin Park, Will Newton,
James Hogan
On 08/23/2012 09:33 PM, Will Newton wrote:
> On Thu, Aug 23, 2012 at 12:31 PM, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>> To avoid glitches in the card clock output,
>> need to check whether card is busy or not.
>>
>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
>> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
>> ---
>> drivers/mmc/host/dw_mmc.c | 30 ++++++++++++++++++++++++------
>> drivers/mmc/host/dw_mmc.h | 1 +
>> 2 files changed, 25 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>> index 36f98c0..8bef3c2 100644
>> --- a/drivers/mmc/host/dw_mmc.c
>> +++ b/drivers/mmc/host/dw_mmc.c
>> @@ -623,6 +623,27 @@ static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
>> cmd, arg, cmd_status);
>> }
>>
>> +static void dw_mci_inform_ciu(struct dw_mci_slot *slot)
>> +{
>> + struct dw_mci *host = slot->host;
>> + unsigned long timeout = jiffies + msecs_to_jiffies(500);
>
> Is there a reason why this timeout value was chosen? It seems quite long.
There is no special reason. I will fix it with more reasonable value.
>
>> + u32 ctrl, status;
>> +
>> + do {
>> + status = mci_readl(host, STATUS);
>> + if (!(status & SDMMC_DATA_BUSY))
>> + break;
>> + ctrl = mci_readl(host, CTRL);
>> + ctrl |= SDMMC_CTRL_RESET;
>> + mci_writel(host, CTRL, ctrl);
>> + } while (time_before(jiffies, timeout));
>> +
>> + if (status & SDMMC_DATA_BUSY)
>> + dev_err(&slot->mmc->class_dev,"Card is busy..!\n");
>
> The two periods in this message do not need to be there.
Will fix.
Best Regards,
Jaehoon Chung
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* RE: [PATCH 2/5] mmc: dw-mmc: ensure that the card is not busy when changing clock.
2012-08-23 11:31 [PATCH 2/5] mmc: dw-mmc: ensure that the card is not busy when changing clock Jaehoon Chung
2012-08-23 12:33 ` Will Newton
@ 2012-08-24 3:55 ` Seungwon Jeon
2012-08-24 4:52 ` Jaehoon Chung
1 sibling, 1 reply; 7+ messages in thread
From: Seungwon Jeon @ 2012-08-24 3:55 UTC (permalink / raw)
To: 'Jaehoon Chung', 'linux-mmc'
Cc: 'Chris Ball', 'Kyungmin Park',
'Will Newton', 'James Hogan'
Hi Jaehoon,
On Thursday, August 23, 2012, Jaehoon Chung <jh80.chung@samsung.com> wrote:
> To avoid glitches in the card clock output,
> need to check whether card is busy or not.
Could you describe the problem more?
In which situation did you meet this?
Thanks,
Seungwon Jeon
>
> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> ---
> drivers/mmc/host/dw_mmc.c | 30 ++++++++++++++++++++++++------
> drivers/mmc/host/dw_mmc.h | 1 +
> 2 files changed, 25 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 36f98c0..8bef3c2 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -623,6 +623,27 @@ static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
> cmd, arg, cmd_status);
> }
>
> +static void dw_mci_inform_ciu(struct dw_mci_slot *slot)
> +{
> + struct dw_mci *host = slot->host;
> + unsigned long timeout = jiffies + msecs_to_jiffies(500);
> + u32 ctrl, status;
> +
> + do {
> + status = mci_readl(host, STATUS);
> + if (!(status & SDMMC_DATA_BUSY))
> + break;
> + ctrl = mci_readl(host, CTRL);
> + ctrl |= SDMMC_CTRL_RESET;
> + mci_writel(host, CTRL, ctrl);
> + } while (time_before(jiffies, timeout));
> +
> + if (status & SDMMC_DATA_BUSY)
> + dev_err(&slot->mmc->class_dev,"Card is busy..!\n");
> +
> + mci_send_cmd(slot, SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
> +}
> +
> static void dw_mci_setup_bus(struct dw_mci_slot *slot)
> {
> struct dw_mci *host = slot->host;
> @@ -650,15 +671,13 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
> mci_writel(host, CLKSRC, 0);
>
> /* inform CIU */
> - mci_send_cmd(slot,
> - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
> + dw_mci_inform_ciu(slot);
>
> /* set clock to desired speed */
> mci_writel(host, CLKDIV, div);
>
> /* inform CIU */
> - mci_send_cmd(slot,
> - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
> + dw_mci_inform_ciu(slot);
>
> /* enable clock; only low power if no SDIO */
> clk_en_a = SDMMC_CLKEN_ENABLE << slot->id;
> @@ -667,8 +686,7 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
> mci_writel(host, CLKENA, clk_en_a);
>
> /* inform CIU */
> - mci_send_cmd(slot,
> - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
> + dw_mci_inform_ciu(slot);
>
> host->current_speed = slot->clock;
> }
> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
> index 15c27e1..b6a1a78 100644
> --- a/drivers/mmc/host/dw_mmc.h
> +++ b/drivers/mmc/host/dw_mmc.h
> @@ -127,6 +127,7 @@
> #define SDMMC_CMD_INDX(n) ((n) & 0x1F)
> /* Status register defines */
> #define SDMMC_GET_FCNT(x) (((x)>>17) & 0x1FFF)
> +#define SDMMC_DATA_BUSY BIT(9)
> /* Internal DMAC interrupt defines */
> #define SDMMC_IDMAC_INT_AI BIT(9)
> #define SDMMC_IDMAC_INT_NI BIT(8)
> --
> 1.7.4.1
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 2/5] mmc: dw-mmc: ensure that the card is not busy when changing clock.
2012-08-24 3:55 ` Seungwon Jeon
@ 2012-08-24 4:52 ` Jaehoon Chung
2012-08-27 1:38 ` Seungwon Jeon
0 siblings, 1 reply; 7+ messages in thread
From: Jaehoon Chung @ 2012-08-24 4:52 UTC (permalink / raw)
To: Seungwon Jeon
Cc: 'Jaehoon Chung', 'linux-mmc',
'Chris Ball', 'Kyungmin Park',
'Will Newton', 'James Hogan'
Hi Seungwon,
On 08/24/2012 12:55 PM, Seungwon Jeon wrote:
> Hi Jaehoon,
>
> On Thursday, August 23, 2012, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>> To avoid glitches in the card clock output,
>> need to check whether card is busy or not.
> Could you describe the problem more?
synopsys spec is mentioned. (7.1 Software/Hardware Restrictions)
"Before disabling clock, ensure that card is not busy due to any previous data command."
> In which situation did you meet this?
At specific board, i found the problem that didn't inform ciu.
(It didn't produce always.)
At that time, i checked the status register whether card is busy or not.
(Start bit of CMD register is cleared, but card is busy.)
Current code didn't check the card status. Just check whether the start-bit cleared.
host regard that command is completed, will send the next command.
But next command didn't issue because Card is busy.
This patch can prevent this situation.
If you have any comment or opinion, please let me know. it's great help to me
Best Regards,
Jaehoon Chung
>
> Thanks,
> Seungwon Jeon
>>
>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
>> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
>> ---
>> drivers/mmc/host/dw_mmc.c | 30 ++++++++++++++++++++++++------
>> drivers/mmc/host/dw_mmc.h | 1 +
>> 2 files changed, 25 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>> index 36f98c0..8bef3c2 100644
>> --- a/drivers/mmc/host/dw_mmc.c
>> +++ b/drivers/mmc/host/dw_mmc.c
>> @@ -623,6 +623,27 @@ static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
>> cmd, arg, cmd_status);
>> }
>>
>> +static void dw_mci_inform_ciu(struct dw_mci_slot *slot)
>> +{
>> + struct dw_mci *host = slot->host;
>> + unsigned long timeout = jiffies + msecs_to_jiffies(500);
>> + u32 ctrl, status;
>> +
>> + do {
>> + status = mci_readl(host, STATUS);
>> + if (!(status & SDMMC_DATA_BUSY))
>> + break;
>> + ctrl = mci_readl(host, CTRL);
>> + ctrl |= SDMMC_CTRL_RESET;
>> + mci_writel(host, CTRL, ctrl);
>> + } while (time_before(jiffies, timeout));
>> +
>> + if (status & SDMMC_DATA_BUSY)
>> + dev_err(&slot->mmc->class_dev,"Card is busy..!\n");
>> +
>> + mci_send_cmd(slot, SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
>> +}
>> +
>> static void dw_mci_setup_bus(struct dw_mci_slot *slot)
>> {
>> struct dw_mci *host = slot->host;
>> @@ -650,15 +671,13 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
>> mci_writel(host, CLKSRC, 0);
>>
>> /* inform CIU */
>> - mci_send_cmd(slot,
>> - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
>> + dw_mci_inform_ciu(slot);
>>
>> /* set clock to desired speed */
>> mci_writel(host, CLKDIV, div);
>>
>> /* inform CIU */
>> - mci_send_cmd(slot,
>> - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
>> + dw_mci_inform_ciu(slot);
>>
>> /* enable clock; only low power if no SDIO */
>> clk_en_a = SDMMC_CLKEN_ENABLE << slot->id;
>> @@ -667,8 +686,7 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
>> mci_writel(host, CLKENA, clk_en_a);
>>
>> /* inform CIU */
>> - mci_send_cmd(slot,
>> - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
>> + dw_mci_inform_ciu(slot);
>>
>> host->current_speed = slot->clock;
>> }
>> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
>> index 15c27e1..b6a1a78 100644
>> --- a/drivers/mmc/host/dw_mmc.h
>> +++ b/drivers/mmc/host/dw_mmc.h
>> @@ -127,6 +127,7 @@
>> #define SDMMC_CMD_INDX(n) ((n) & 0x1F)
>> /* Status register defines */
>> #define SDMMC_GET_FCNT(x) (((x)>>17) & 0x1FFF)
>> +#define SDMMC_DATA_BUSY BIT(9)
>> /* Internal DMAC interrupt defines */
>> #define SDMMC_IDMAC_INT_AI BIT(9)
>> #define SDMMC_IDMAC_INT_NI BIT(8)
>> --
>> 1.7.4.1
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* RE: [PATCH 2/5] mmc: dw-mmc: ensure that the card is not busy when changing clock.
2012-08-24 4:52 ` Jaehoon Chung
@ 2012-08-27 1:38 ` Seungwon Jeon
2012-08-27 1:51 ` Jaehoon Chung
0 siblings, 1 reply; 7+ messages in thread
From: Seungwon Jeon @ 2012-08-27 1:38 UTC (permalink / raw)
To: 'Jaehoon Chung'
Cc: 'linux-mmc', 'Chris Ball',
'Kyungmin Park', 'Will Newton',
'James Hogan'
On Friday, August 24, 2012, Jaehoon Chung <jh80.chung@samsung.com> wrote:
> Hi Seungwon,
>
> On 08/24/2012 12:55 PM, Seungwon Jeon wrote:
> > Hi Jaehoon,
> >
> > On Thursday, August 23, 2012, Jaehoon Chung <jh80.chung@samsung.com> wrote:
> >> To avoid glitches in the card clock output,
> >> need to check whether card is busy or not.
> > Could you describe the problem more?
> synopsys spec is mentioned. (7.1 Software/Hardware Restrictions)
> "Before disabling clock, ensure that card is not busy due to any previous data command."
>
> > In which situation did you meet this?
> At specific board, i found the problem that didn't inform ciu.
> (It didn't produce always.)
> At that time, i checked the status register whether card is busy or not.
> (Start bit of CMD register is cleared, but card is busy.)
> Current code didn't check the card status. Just check whether the start-bit cleared.
> host regard that command is completed, will send the next command.
> But next command didn't issue because Card is busy.
> This patch can prevent this situation.
>
> If you have any comment or opinion, please let me know. it's great help to me
If you know a point in time, we can reproduce it.
>
> Best Regards,
> Jaehoon Chung
> >
> > Thanks,
> > Seungwon Jeon
> >>
> >> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
> >> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> >> ---
> >> drivers/mmc/host/dw_mmc.c | 30 ++++++++++++++++++++++++------
> >> drivers/mmc/host/dw_mmc.h | 1 +
> >> 2 files changed, 25 insertions(+), 6 deletions(-)
> >>
> >> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> >> index 36f98c0..8bef3c2 100644
> >> --- a/drivers/mmc/host/dw_mmc.c
> >> +++ b/drivers/mmc/host/dw_mmc.c
> >> @@ -623,6 +623,27 @@ static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
> >> cmd, arg, cmd_status);
> >> }
> >>
> >> +static void dw_mci_inform_ciu(struct dw_mci_slot *slot)
> >> +{
> >> + struct dw_mci *host = slot->host;
> >> + unsigned long timeout = jiffies + msecs_to_jiffies(500);
> >> + u32 ctrl, status;
> >> +
> >> + do {
> >> + status = mci_readl(host, STATUS);
> >> + if (!(status & SDMMC_DATA_BUSY))
> >> + break;
> >> + ctrl = mci_readl(host, CTRL);
> >> + ctrl |= SDMMC_CTRL_RESET;
> >> + mci_writel(host, CTRL, ctrl);
> >> + } while (time_before(jiffies, timeout));
> >> +
> >> + if (status & SDMMC_DATA_BUSY)
> >> + dev_err(&slot->mmc->class_dev,"Card is busy..!\n");
> >> +
> >> + mci_send_cmd(slot, SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
> >> +}
> >> +
> >> static void dw_mci_setup_bus(struct dw_mci_slot *slot)
> >> {
> >> struct dw_mci *host = slot->host;
> >> @@ -650,15 +671,13 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
> >> mci_writel(host, CLKSRC, 0);
> >>
> >> /* inform CIU */
> >> - mci_send_cmd(slot,
> >> - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
> >> + dw_mci_inform_ciu(slot);
> >>
> >> /* set clock to desired speed */
> >> mci_writel(host, CLKDIV, div);
> >>
> >> /* inform CIU */
> >> - mci_send_cmd(slot,
> >> - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
> >> + dw_mci_inform_ciu(slot);
> >>
> >> /* enable clock; only low power if no SDIO */
> >> clk_en_a = SDMMC_CLKEN_ENABLE << slot->id;
> >> @@ -667,8 +686,7 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
> >> mci_writel(host, CLKENA, clk_en_a);
> >>
> >> /* inform CIU */
> >> - mci_send_cmd(slot,
> >> - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
> >> + dw_mci_inform_ciu(slot);
> >>
> >> host->current_speed = slot->clock;
> >> }
> >> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
> >> index 15c27e1..b6a1a78 100644
> >> --- a/drivers/mmc/host/dw_mmc.h
> >> +++ b/drivers/mmc/host/dw_mmc.h
> >> @@ -127,6 +127,7 @@
> >> #define SDMMC_CMD_INDX(n) ((n) & 0x1F)
> >> /* Status register defines */
> >> #define SDMMC_GET_FCNT(x) (((x)>>17) & 0x1FFF)
> >> +#define SDMMC_DATA_BUSY BIT(9)
> >> /* Internal DMAC interrupt defines */
> >> #define SDMMC_IDMAC_INT_AI BIT(9)
> >> #define SDMMC_IDMAC_INT_NI BIT(8)
> >> --
> >> 1.7.4.1
> >> --
> >> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> >> the body of a message to majordomo@vger.kernel.org
> >> More majordomo info at http://vger.kernel.org/majordomo-info.html
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> >
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 2/5] mmc: dw-mmc: ensure that the card is not busy when changing clock.
2012-08-27 1:38 ` Seungwon Jeon
@ 2012-08-27 1:51 ` Jaehoon Chung
0 siblings, 0 replies; 7+ messages in thread
From: Jaehoon Chung @ 2012-08-27 1:51 UTC (permalink / raw)
To: Seungwon Jeon
Cc: 'Jaehoon Chung', 'linux-mmc',
'Chris Ball', 'Kyungmin Park',
'Will Newton', 'James Hogan'
On 08/27/2012 10:38 AM, Seungwon Jeon wrote:
> On Friday, August 24, 2012, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>> Hi Seungwon,
>>
>> On 08/24/2012 12:55 PM, Seungwon Jeon wrote:
>>> Hi Jaehoon,
>>>
>>> On Thursday, August 23, 2012, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>>>> To avoid glitches in the card clock output,
>>>> need to check whether card is busy or not.
>>> Could you describe the problem more?
>> synopsys spec is mentioned. (7.1 Software/Hardware Restrictions)
>> "Before disabling clock, ensure that card is not busy due to any previous data command."
>>
>>> In which situation did you meet this?
>> At specific board, i found the problem that didn't inform ciu.
>> (It didn't produce always.)
>> At that time, i checked the status register whether card is busy or not.
>> (Start bit of CMD register is cleared, but card is busy.)
>> Current code didn't check the card status. Just check whether the start-bit cleared.
>> host regard that command is completed, will send the next command.
>> But next command didn't issue because Card is busy.
>> This patch can prevent this situation.
>>
>> If you have any comment or opinion, please let me know. it's great help to me
> If you know a point in time, we can reproduce it.
Well, i didn't sure that you can reproduce this.
On trats board, this problem is produced when kernel is booting.
Best Regards,
Jaehoon Chung
>
>>
>> Best Regards,
>> Jaehoon Chung
>>>
>>> Thanks,
>>> Seungwon Jeon
>>>>
>>>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
>>>> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
>>>> ---
>>>> drivers/mmc/host/dw_mmc.c | 30 ++++++++++++++++++++++++------
>>>> drivers/mmc/host/dw_mmc.h | 1 +
>>>> 2 files changed, 25 insertions(+), 6 deletions(-)
>>>>
>>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>>>> index 36f98c0..8bef3c2 100644
>>>> --- a/drivers/mmc/host/dw_mmc.c
>>>> +++ b/drivers/mmc/host/dw_mmc.c
>>>> @@ -623,6 +623,27 @@ static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
>>>> cmd, arg, cmd_status);
>>>> }
>>>>
>>>> +static void dw_mci_inform_ciu(struct dw_mci_slot *slot)
>>>> +{
>>>> + struct dw_mci *host = slot->host;
>>>> + unsigned long timeout = jiffies + msecs_to_jiffies(500);
>>>> + u32 ctrl, status;
>>>> +
>>>> + do {
>>>> + status = mci_readl(host, STATUS);
>>>> + if (!(status & SDMMC_DATA_BUSY))
>>>> + break;
>>>> + ctrl = mci_readl(host, CTRL);
>>>> + ctrl |= SDMMC_CTRL_RESET;
>>>> + mci_writel(host, CTRL, ctrl);
>>>> + } while (time_before(jiffies, timeout));
>>>> +
>>>> + if (status & SDMMC_DATA_BUSY)
>>>> + dev_err(&slot->mmc->class_dev,"Card is busy..!\n");
>>>> +
>>>> + mci_send_cmd(slot, SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
>>>> +}
>>>> +
>>>> static void dw_mci_setup_bus(struct dw_mci_slot *slot)
>>>> {
>>>> struct dw_mci *host = slot->host;
>>>> @@ -650,15 +671,13 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
>>>> mci_writel(host, CLKSRC, 0);
>>>>
>>>> /* inform CIU */
>>>> - mci_send_cmd(slot,
>>>> - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
>>>> + dw_mci_inform_ciu(slot);
>>>>
>>>> /* set clock to desired speed */
>>>> mci_writel(host, CLKDIV, div);
>>>>
>>>> /* inform CIU */
>>>> - mci_send_cmd(slot,
>>>> - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
>>>> + dw_mci_inform_ciu(slot);
>>>>
>>>> /* enable clock; only low power if no SDIO */
>>>> clk_en_a = SDMMC_CLKEN_ENABLE << slot->id;
>>>> @@ -667,8 +686,7 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot)
>>>> mci_writel(host, CLKENA, clk_en_a);
>>>>
>>>> /* inform CIU */
>>>> - mci_send_cmd(slot,
>>>> - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0);
>>>> + dw_mci_inform_ciu(slot);
>>>>
>>>> host->current_speed = slot->clock;
>>>> }
>>>> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
>>>> index 15c27e1..b6a1a78 100644
>>>> --- a/drivers/mmc/host/dw_mmc.h
>>>> +++ b/drivers/mmc/host/dw_mmc.h
>>>> @@ -127,6 +127,7 @@
>>>> #define SDMMC_CMD_INDX(n) ((n) & 0x1F)
>>>> /* Status register defines */
>>>> #define SDMMC_GET_FCNT(x) (((x)>>17) & 0x1FFF)
>>>> +#define SDMMC_DATA_BUSY BIT(9)
>>>> /* Internal DMAC interrupt defines */
>>>> #define SDMMC_IDMAC_INT_AI BIT(9)
>>>> #define SDMMC_IDMAC_INT_NI BIT(8)
>>>> --
>>>> 1.7.4.1
>>>> --
>>>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
>>>> the body of a message to majordomo@vger.kernel.org
>>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>>
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>>
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2012-08-27 1:51 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-08-23 11:31 [PATCH 2/5] mmc: dw-mmc: ensure that the card is not busy when changing clock Jaehoon Chung
2012-08-23 12:33 ` Will Newton
2012-08-23 13:26 ` Jaehoon Chung
2012-08-24 3:55 ` Seungwon Jeon
2012-08-24 4:52 ` Jaehoon Chung
2012-08-27 1:38 ` Seungwon Jeon
2012-08-27 1:51 ` Jaehoon Chung
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox