Re: [PATCH 01/16] remoteproc: q6v5-mss: fixup MSM8998 MSS out of reset sequence

From: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
To: Sibi Sankar <sibis@codeaurora.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>,
	Jeffrey Hugo <jhugo@codeaurora.org>,
	Rob Herring <robh+dt@kernel.org>,
	Jonathan Marek <jonathan@marek.ca>,
	Ohad Ben-Cohen <ohad@wizery.com>,
	Mark Rutland <mark.rutland@arm.com>,
	p.zabel@pengutronix.de, MSM <linux-arm-msm@vger.kernel.org>,
	linux-remoteproc@vger.kernel.org,
	DTML <devicetree@vger.kernel.org>,
	lkml <linux-kernel@vger.kernel.org>,
	Andy Gross <agross@kernel.org>
Subject: Re: [PATCH 01/16] remoteproc: q6v5-mss: fixup MSM8998 MSS out of reset sequence
Date: Mon, 18 Nov 2019 14:54:54 -0700	[thread overview]
Message-ID: <CAOCk7Nou94bxk_48JArrXhQw2KR+3bKanLe+hb2=d7_j6y3VbQ@mail.gmail.com> (raw)
In-Reply-To: <0101016e80782dd7-2617455b-7d73-4e68-8a9a-b63c29e9ad76-000000@us-west-2.amazonses.com>

On Mon, Nov 18, 2019 at 2:43 PM Sibi Sankar <sibis@codeaurora.org> wrote:
>
> Fixup the following in the MSS out of reset sequence on MSM8998:
> * skip ACC override on MSM8998.
> * wait for BHS_EN_REST_ACK to be set before setting the LDO to bypass.
> * remove "mem" clock from the active pool.

Why any of this is necessary isn't explained.
Seems like it should be 3 separate patches.
Regarding the mem clock change, wouldn't it be an issue if we don't
vote for that?

>
> Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
> ---
>  drivers/remoteproc/qcom_q6v5_mss.c | 23 ++++++++++++++++++++---
>  1 file changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/remoteproc/qcom_q6v5_mss.c b/drivers/remoteproc/qcom_q6v5_mss.c
> index 471128a2e7239..2becf6dade936 100644
> --- a/drivers/remoteproc/qcom_q6v5_mss.c
> +++ b/drivers/remoteproc/qcom_q6v5_mss.c
> @@ -100,6 +100,11 @@
>  #define QDSP6SS_XO_CBCR                0x0038
>  #define QDSP6SS_ACC_OVERRIDE_VAL               0x20
>
> +/* QDSP6v62 parameters */
> +#define QDSP6SS_BHS_EN_REST_ACK                BIT(0)
> +#define BHS_CHECK_MAX_LOOPS            200
> +#define QDSP6SS_BHS_STATUS             0x0C4
> +
>  /* QDSP6v65 parameters */
>  #define QDSP6SS_SLEEP                   0x3C
>  #define QDSP6SS_BOOT_CORE_START         0x400
> @@ -505,8 +510,9 @@ static int q6v5proc_reset(struct q6v5 *qproc)
>                 int mem_pwr_ctl;
>
>                 /* Override the ACC value if required */
> -               writel(QDSP6SS_ACC_OVERRIDE_VAL,
> -                      qproc->reg_base + QDSP6SS_STRAP_ACC);
> +               if (qproc->version == MSS_MSM8996)
> +                       writel(QDSP6SS_ACC_OVERRIDE_VAL,
> +                              qproc->reg_base + QDSP6SS_STRAP_ACC);
>
>                 /* Assert resets, stop core */
>                 val = readl(qproc->reg_base + QDSP6SS_RESET_REG);
> @@ -534,6 +540,18 @@ static int q6v5proc_reset(struct q6v5 *qproc)
>                 val |= readl(qproc->reg_base + QDSP6SS_PWR_CTL_REG);
>                 udelay(1);
>
> +               /* wait for BHS_EN_REST_ACK to be set */
> +               if (qproc->version == MSS_MSM8998) {
> +                       ret = readl_poll_timeout(qproc->reg_base + QDSP6SS_BHS_STATUS,
> +                                                val, (val & QDSP6SS_BHS_EN_REST_ACK),
> +                                                1, BHS_CHECK_MAX_LOOPS);
> +                       if (ret) {
> +                               dev_err(qproc->dev,
> +                                       "QDSP6SS_BHS_EN_REST_ACK timedout\n");
> +                               return -ETIMEDOUT;
> +                       }
> +               }
> +
>                 /* Put LDO in bypass mode */
>                 val |= QDSP6v56_LDO_BYP;
>                 writel(val, qproc->reg_base + QDSP6SS_PWR_CTL_REG);
> @@ -1594,7 +1612,6 @@ static const struct rproc_hexagon_res msm8998_mss = {
>         .active_clk_names = (char*[]){
>                         "iface",
>                         "bus",
> -                       "mem",
>                         "gpll0_mss",
>                         "mnoc_axi",
>                         "snoc_axi",
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>