Re: [PATCH] mmc: core: skip mmc_power_up call from start host

2012-08-20 Thread Ulf Hansson 
Hi Girish,

On 13 July 2012 14:57, Girish K S girish.shivananja...@linaro.org wrote:
 The call to the mmc_power_up during the mmc_start_host breaks the card
 detection in design-ware host controller. This patch removes the call to
 mmc_power_up function during host start.

 This fix works fine with sdhci (sdhci compatilble host controller)
 and dw_mmc (design-ware host controller). and has no side effect due to
 this removal.

 Tested on : origen-board and smdk-5250 board.

 Signed-off-by: Girish K S girish.shivananja...@linaro.org
 Cc: Ulf Hansson ulf.hans...@linaro.org
 ---
  drivers/mmc/core/core.c |1 -
  1 files changed, 0 insertions(+), 1 deletions(-)

 diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
 index 9503cab..503aefc 100644
 --- a/drivers/mmc/core/core.c
 +++ b/drivers/mmc/core/core.c
 @@ -2108,7 +2108,6 @@ void mmc_start_host(struct mmc_host *host)
  {
 host-f_init = max(freqs[0], host-f_min);
 host-rescan_disable = 0;
 -   mmc_power_up(host);

This will introduce a bug (race condition) for host drivers using the
regulator API (from regulator_init_complete) and for eMMC. So please
do not remove this.

 mmc_detect_change(host, 0);
  }

 --
 1.7.4.1



I suggest you find out more details about why this breaks the card
detection mechanism for your stated boards.

Kind regards
Ulf Hansson
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Re: [PATCH] mmc: core: skip mmc_power_up call from start host

2012-07-17 Thread S, Venkatraman 
On Fri, Jul 13, 2012 at 6:27 PM, Girish K S
girish.shivananja...@linaro.org wrote:
 The call to the mmc_power_up during the mmc_start_host breaks the card
 detection in design-ware host controller. This patch removes the call to
 mmc_power_up function during host start.

Please explain why. Which commit introduced it ?

 This fix works fine with sdhci (sdhci compatilble host controller)
 and dw_mmc (design-ware host controller). and has no side effect due to
 this removal.

How can you be sure ? What about other hosts ?
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Re: [PATCH] mmc: core: skip mmc_power_up call from start host

2012-07-17 Thread Girish K S 
On 17 July 2012 16:22, S, Venkatraman svenk...@ti.com wrote:
 On Fri, Jul 13, 2012 at 6:27 PM, Girish K S
 girish.shivananja...@linaro.org wrote:
 The call to the mmc_power_up during the mmc_start_host breaks the card
 detection in design-ware host controller. This patch removes the call to
 mmc_power_up function during host start.

 Please explain why. Which commit introduced it ?
dw_mmc card detection is broken by this commit
fa5501890d8974301042e0202d342a6cbe8609f4

 This fix works fine with sdhci (sdhci compatilble host controller)
 and dw_mmc (design-ware host controller). and has no side effect due to
 this removal.

 How can you be sure ? What about other hosts ?
I have tested on the available host controllers. It would be helpful
if others test it and let me know whether this change of mine causes
any problem.
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[PATCH] mmc: core: skip mmc_power_up call from start host

2012-07-13 Thread Girish K S 
The call to the mmc_power_up during the mmc_start_host breaks the card
detection in design-ware host controller. This patch removes the call to
mmc_power_up function during host start.

This fix works fine with sdhci (sdhci compatilble host controller)
and dw_mmc (design-ware host controller). and has no side effect due to
this removal.

Tested on : origen-board and smdk-5250 board.

Signed-off-by: Girish K S girish.shivananja...@linaro.org
Cc: Ulf Hansson ulf.hans...@linaro.org
---
 drivers/mmc/core/core.c |1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 9503cab..503aefc 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2108,7 +2108,6 @@ void mmc_start_host(struct mmc_host *host)
 {
host-f_init = max(freqs[0], host-f_min);
host-rescan_disable = 0;
-   mmc_power_up(host);
mmc_detect_change(host, 0);
 }
 
-- 
1.7.4.1

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