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Subject: Re: [PATCH AUTOSEL 5.5 219/542] ARM: OMAP2+: use separate IOMMU pdata
 to fix DRA7 IPU1 boot
To:     Sasha Levin <sashal@kernel.org>, <linux-kernel@vger.kernel.org>,
        <stable@vger.kernel.org>
CC:     Tony Lindgren <tony@atomide.com>, <linux-omap@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>
References: <20200214154854.6746-1-sashal@kernel.org>
 <20200214154854.6746-219-sashal@kernel.org>
From:   Suman Anna <s-anna@ti.com>
Message-ID: <a7666322-f931-63f1-a4c5-d44c2ba4ed0c@ti.com>
Date:   Fri, 14 Feb 2020 12:34:58 -0600
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Hi Sasha,

On 2/14/20 9:43 AM, Sasha Levin wrote:
> From: Suman Anna <s-anna@ti.com>
> 
> [ Upstream commit 4601832f40501efc3c2fd264a5a69bd1ac17d520 ]
> 
> The IPU1 MMU has been using common IOMMU pdata quirks defined and
> used by all IPU IOMMU devices on OMAP4 and beyond. Separate out the
> pdata for IPU1 MMU with the additional .set_pwrdm_constraint ops
> plugged in, so that the IPU1 power domain can be restricted to ON
> state during the boot and active period of the IPU1 remote processor.
> This eliminates the pre-conditions for the IPU1 boot issue as
> described in commit afe518400bdb ("iommu/omap: fix boot issue on
> remoteprocs with AMMU/Unicache").
> 
> NOTE:
> 1. RET is not a valid target power domain state on DRA7 platforms,
>    and IPU power domain is normally programmed for OFF. The IPU1
>    still fails to boot though, and an unclearable l3_noc error is
>    thrown currently on 4.14 kernel without this fix. This behavior
>    is slightly different from previous 4.9 LTS kernel.
> 2. The fix is currently applied only to IPU1 on DRA7xx SoC, as the
>    other affected processors on OMAP4/OMAP5/DRA7 are in domains
>    that are not entering RET. IPU2 on DRA7 is in CORE power domain
>    which is only programmed for ON power state. The fix can be easily
>    scaled if these domains do hit RET in the future.
> 3. The issue was not seen on current DRA7 platforms if any of the
>    DSP remote processors were booted and using one of the GPTimers
>    5, 6, 7 or 8 on previous 4.9 LTS kernel. This was due to the
>    errata fix for i874 implemented in commit 1cbabcb9807e ("ARM:
>    DRA7: clockdomain: Implement timer workaround for errata i874")
>    which keeps the IPU1 power domain from entering RET when the
>    timers are active. But the timer workaround did not make any
>    difference on 4.14 kernel, and an l3_noc error was seen still
>    without this fix.
> 
> Signed-off-by: Suman Anna <s-anna@ti.com>
> Signed-off-by: Tony Lindgren <tony@atomide.com>
> Signed-off-by: Sasha Levin <sashal@kernel.org>

And drop this one as well, since mainline doesn't yet boot
the processors, so this is not needed for stable queue.

regards
Suman

> ---
>  arch/arm/mach-omap2/pdata-quirks.c | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
> 
> diff --git a/arch/arm/mach-omap2/pdata-quirks.c b/arch/arm/mach-omap2/pdata-quirks.c
> index 7a79bcc02a11b..c3be1db9685cd 100644
> --- a/arch/arm/mach-omap2/pdata-quirks.c
> +++ b/arch/arm/mach-omap2/pdata-quirks.c
> @@ -43,6 +43,17 @@ struct pdata_init {
>  static struct of_dev_auxdata omap_auxdata_lookup[];
>  static struct twl4030_gpio_platform_data twl_gpio_auxdata;
>  
> +#if IS_ENABLED(CONFIG_OMAP_IOMMU)
> +int omap_iommu_set_pwrdm_constraint(struct platform_device *pdev, bool request,
> +				    u8 *pwrst);
> +#else
> +static inline int omap_iommu_set_pwrdm_constraint(struct platform_device *pdev,
> +						  bool request, u8 *pwrst)
> +{
> +	return 0;
> +}
> +#endif
> +
>  #ifdef CONFIG_MACH_NOKIA_N8X0
>  static void __init omap2420_n8x0_legacy_init(void)
>  {
> @@ -286,6 +297,10 @@ static void __init omap5_uevm_legacy_init(void)
>  #endif
>  
>  #ifdef CONFIG_SOC_DRA7XX
> +static struct iommu_platform_data dra7_ipu1_dsp_iommu_pdata = {
> +	.set_pwrdm_constraint = omap_iommu_set_pwrdm_constraint,
> +};
> +
>  static struct omap_hsmmc_platform_data dra7_hsmmc_data_mmc1;
>  static struct omap_hsmmc_platform_data dra7_hsmmc_data_mmc2;
>  static struct omap_hsmmc_platform_data dra7_hsmmc_data_mmc3;
> @@ -517,6 +532,12 @@ static struct of_dev_auxdata omap_auxdata_lookup[] = {
>  		       &dra7_hsmmc_data_mmc2),
>  	OF_DEV_AUXDATA("ti,dra7-hsmmc", 0x480ad000, "480ad000.mmc",
>  		       &dra7_hsmmc_data_mmc3),
> +	OF_DEV_AUXDATA("ti,dra7-dsp-iommu", 0x40d01000, "40d01000.mmu",
> +		       &dra7_ipu1_dsp_iommu_pdata),
> +	OF_DEV_AUXDATA("ti,dra7-dsp-iommu", 0x41501000, "41501000.mmu",
> +		       &dra7_ipu1_dsp_iommu_pdata),
> +	OF_DEV_AUXDATA("ti,dra7-iommu", 0x58882000, "58882000.mmu",
> +		       &dra7_ipu1_dsp_iommu_pdata),
>  #endif
>  	/* Common auxdata */
>  	OF_DEV_AUXDATA("ti,sysc", 0, NULL, &ti_sysc_pdata),
>