Re: [RESEND, PATCH] mmc: sdhci-pci-gli: A workaround to allow GL9755 to enter ASPM L1.2

From: Ulf Hansson <ulf.hansson@linaro.org>
To: Ben Chuang <benchuanggli@gmail.com>
Cc: adrian.hunter@intel.com, SeanHY.Chen@genesyslogic.com.tw,
	ben.chuang@genesyslogic.com.tw, greg.tu@genesyslogic.com.tw,
	linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org
Subject: Re: [RESEND, PATCH] mmc: sdhci-pci-gli: A workaround to allow GL9755 to enter ASPM L1.2
Date: Thu, 21 Apr 2022 15:54:31 +0200	[thread overview]
Message-ID: <CAPDyKFo2YhqgEStGcQb0ZWcuhrUcGeamgHk1Hov6_DzS=TNe3A@mail.gmail.com> (raw)
In-Reply-To: <20220414094945.457500-1-benchuanggli@gmail.com>

On Thu, 14 Apr 2022 at 11:49, Ben Chuang <benchuanggli@gmail.com> wrote:
>
> From: Ben Chuang <ben.chuang@genesyslogic.com.tw>
>
> When GL9755 enters ASPM L1 sub-states, it will stay at L1.1 and will not
> enter L1.2. The workaround is to toggle PM state to allow GL9755 to enter
> ASPM L1.2.
>
> Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>

This didn't apply cleanly, I fixed it up this time. So, applied for
next, thanks!

Kind regards
Uffe

> ---
>  drivers/mmc/host/sdhci-pci-gli.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-pci-gli.c b/drivers/mmc/host/sdhci-pci-gli.c
> index 97035d77c18c..52230857388f 100644
> --- a/drivers/mmc/host/sdhci-pci-gli.c
> +++ b/drivers/mmc/host/sdhci-pci-gli.c
> @@ -137,6 +137,9 @@
>  #define PCI_GLI_9755_SerDes  0x70
>  #define PCI_GLI_9755_SCP_DIS   BIT(19)
>
> +#define PCI_GLI_9755_PM_CTRL     0xFC
> +#define   PCI_GLI_9755_PM_STATE    GENMASK(1, 0)
> +
>  #define GLI_MAX_TUNING_LOOP 40
>
>  /* Genesys Logic chipset */
> @@ -597,6 +600,13 @@ static void gl9755_hw_setting(struct sdhci_pci_slot *slot)
>                             GLI_9755_CFG2_L1DLY_VALUE);
>         pci_write_config_dword(pdev, PCI_GLI_9755_CFG2, value);
>
> +       /* toggle PM state to allow GL9755 to enter ASPM L1.2 */
> +       pci_read_config_dword(pdev, PCI_GLI_9755_PM_CTRL, &value);
> +       value |= PCI_GLI_9755_PM_STATE;
> +       pci_write_config_dword(pdev, PCI_GLI_9755_PM_CTRL, value);
> +       value &= ~PCI_GLI_9755_PM_STATE;
> +       pci_write_config_dword(pdev, PCI_GLI_9755_PM_CTRL, value);
> +
>         gl9755_wt_off(pdev);
>  }
>
> --
> 2.35.1
>