| Message ID | 1342184235-6912-1-git-send-email-girish.shivananjappa@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Fri, Jul 13, 2012 at 6:27 PM, Girish K S <girish.shivananjappa@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 ?
On 17 July 2012 16:22, S, Venkatraman <svenkatr@ti.com> wrote: > On Fri, Jul 13, 2012 at 6:27 PM, Girish K S > <girish.shivananjappa@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.
Hi Girish, On 13 July 2012 14:57, Girish K S <girish.shivananjappa@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.shivananjappa@linaro.org> > Cc: Ulf Hansson <ulf.hansson@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
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); }
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.shivananjappa@linaro.org> Cc: Ulf Hansson <ulf.hansson@linaro.org> --- drivers/mmc/core/core.c | 1 - 1 files changed, 0 insertions(+), 1 deletions(-)