2020-08-27 15:23:42

by Veerabhadrarao Badiganti

[permalink] [raw]
Subject: [PATCH] mmc: sdhci-msm: Enable restore_dll_config flag for sc7180 target

On sc7180 target, issues are observed with HS400 mode due to a
hardware limitation. If sdcc clock is dynamically gated and ungated,
the very next command is failing with command CRC/timeout errors.

To mitigate this issue, DLL phase has to be restored whenever sdcc
clock is gated dynamically. The restore_dll_config ensures this.
Enabling this flag with this change. And simply re-using the sdm845
target configuration for this flag.

Signed-off-by: Veerabhadrarao Badiganti <[email protected]>
---
drivers/mmc/host/sdhci-msm.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 5a33389037cd..d4c02884cca8 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -2151,6 +2151,7 @@ static void sdhci_msm_dump_vendor_regs(struct sdhci_host *host)
{.compatible = "qcom,sdhci-msm-v5", .data = &sdhci_msm_v5_var},
{.compatible = "qcom,sdm845-sdhci", .data = &sdm845_sdhci_var},
{.compatible = "qcom,sm8250-sdhci", .data = &sm8250_sdhci_var},
+ {.compatible = "qcom,sc7180-sdhci", .data = &sdm845_sdhci_var},
{},
};

--
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc., is a member of Code Aurora Forum, a Linux Foundation Collaborative Project


2020-08-27 15:45:15

by Doug Anderson

[permalink] [raw]
Subject: Re: [PATCH] mmc: sdhci-msm: Enable restore_dll_config flag for sc7180 target

Hi,

On Thu, Aug 27, 2020 at 8:22 AM Veerabhadrarao Badiganti
<[email protected]> wrote:
>
> On sc7180 target, issues are observed with HS400 mode due to a
> hardware limitation. If sdcc clock is dynamically gated and ungated,
> the very next command is failing with command CRC/timeout errors.
>
> To mitigate this issue, DLL phase has to be restored whenever sdcc
> clock is gated dynamically. The restore_dll_config ensures this.
> Enabling this flag with this change. And simply re-using the sdm845
> target configuration for this flag.
>
> Signed-off-by: Veerabhadrarao Badiganti <[email protected]>
> ---
> drivers/mmc/host/sdhci-msm.c | 1 +
> 1 file changed, 1 insertion(+)

Whoops! I was too busy debugging and preparing patches and didn't
realize that you'd already sent this. Sorry for sending it too.
Let's take yours.

Reviewed-by: Douglas Anderson <[email protected]>
Tested-by: Douglas Anderson <[email protected]>

2020-08-28 08:55:41

by Ulf Hansson

[permalink] [raw]
Subject: Re: [PATCH] mmc: sdhci-msm: Enable restore_dll_config flag for sc7180 target

On Thu, 27 Aug 2020 at 17:22, Veerabhadrarao Badiganti
<[email protected]> wrote:
>
> On sc7180 target, issues are observed with HS400 mode due to a
> hardware limitation. If sdcc clock is dynamically gated and ungated,
> the very next command is failing with command CRC/timeout errors.
>
> To mitigate this issue, DLL phase has to be restored whenever sdcc
> clock is gated dynamically. The restore_dll_config ensures this.
> Enabling this flag with this change. And simply re-using the sdm845
> target configuration for this flag.
>
> Signed-off-by: Veerabhadrarao Badiganti <[email protected]>

Applied for next, thanks!

Kind regards
Uffe

> ---
> drivers/mmc/host/sdhci-msm.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 5a33389037cd..d4c02884cca8 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -2151,6 +2151,7 @@ static void sdhci_msm_dump_vendor_regs(struct sdhci_host *host)
> {.compatible = "qcom,sdhci-msm-v5", .data = &sdhci_msm_v5_var},
> {.compatible = "qcom,sdm845-sdhci", .data = &sdm845_sdhci_var},
> {.compatible = "qcom,sm8250-sdhci", .data = &sm8250_sdhci_var},
> + {.compatible = "qcom,sc7180-sdhci", .data = &sdm845_sdhci_var},
> {},
> };
>
> --
> Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc., is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
>