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SubjectRe: [v2] mmc: sdhci-msm: Optionally wait for signal level changes
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On Montag, 20. November 2017 20:56:47 CET Bjorn Andersson wrote:
> Not all instances of the SDCC core supports changing signal voltage and
> as such will not generate a power interrupt when the software attempts
> to change the voltage. This results in probing the eMMC on some devices
> to take over 2 minutes.
>
> Check that the SWITCHABLE_SIGNALING_VOLTAGE bit in MCI_GENERICS is set
> before waiting for the power interrupt.
>
> Cc: Sahitya Tummala <stummala@codeaurora.org>
> Cc: Vijay Viswanath <vviswana@codeaurora.org>
> Fixes: c0309b3803fe ("mmc: sdhci-msm: Add sdhci msm register write APIs
> which wait for pwr irq") Signed-off-by: Bjorn Andersson
> <bjorn.andersson@linaro.org>
Tested-by: Luca Weiss <luca@z3ntu.xyz>
> ---
>
> The offending patch is part of your v4.15 pull request, so please pick
> this up for the -rcs.
>
> Changes since v1:
> - Fixed spelling of swichable...
>
> drivers/mmc/host/sdhci-msm.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 3fb7d2eec93f..c283291db705 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -29,6 +29,9 @@
> #define CORE_VERSION_MAJOR_MASK (0xf << CORE_VERSION_MAJOR_SHIFT)
> #define CORE_VERSION_MINOR_MASK 0xff
>
> +#define CORE_MCI_GENERICS 0x70
> +#define SWITCHABLE_SIGNALING_VOLTAGE BIT(29)
> +
> #define CORE_HC_MODE 0x78
> #define HC_MODE_EN 0x1
> #define CORE_POWER 0x0
> @@ -1028,11 +1031,22 @@ static void sdhci_msm_check_power_status(struct
> sdhci_host *host, u32 req_type) struct sdhci_pltfm_host *pltfm_host =
> sdhci_priv(host);
> struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> bool done = false;
> + u32 val;
>
> pr_debug("%s: %s: request %d curr_pwr_state %x curr_io_level %x\n",
> mmc_hostname(host->mmc), __func__, req_type,
> msm_host->curr_pwr_state, msm_host->curr_io_level);
>
> + /*
> + * The power interrupt will not be generated for signal voltage
> + * switches if SWITCHABLE_SIGNALING_VOLTAGE in MCI_GENERICS is not set.
> + */
> + val = readl(msm_host->core_mem + CORE_MCI_GENERICS);
> + if ((req_type & REQ_IO_HIGH || req_type & REQ_IO_LOW) &&
> + !(val & SWITCHABLE_SIGNALING_VOLTAGE)) {
> + return;
> + }
> +
> /*
> * The IRQ for request type IO High/LOW will be generated when -
> * there is a state change in 1.8V enable bit (bit 3) of


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