From: "santosh.shilimkar@oracle.com" <santosh.shilimkar@oracle.com>
To: Keerthy <j-keerthy@ti.com>,
linus.walleij@linaro.org, grygorii.strashko@ti.com,
tony@atomide.com
Cc: t-kristo@ti.com, Russ.Dill@ti.com, linux-omap@vger.kernel.org,
linux-kernel@vger.kernel.org, ssantosh@kernel.org,
haojian.zhuang@linaro.org, linux-arm-kernel@lists.infradead.org,
d-gerlach@ti.com
Subject: Re: [PATCH 01/14] memory: ti-emif-sram: Add resume function to recopy sram code
Date: Thu, 12 Apr 2018 10:44:10 -0600 [thread overview]
Message-ID: <31688cf4-b6ca-e7ce-3407-46262006b38f@oracle.com> (raw)
In-Reply-To: <1523505239-16229-2-git-send-email-j-keerthy@ti.com>
On 4/11/18 9:53 PM, Keerthy wrote:
> From: Dave Gerlach <d-gerlach@ti.com>
>
> After an RTC+DDR cycle we lose sram context so emif pm functions present
> in sram are lost. We can check if the first byte of the original
> code in DDR contains the same first byte as the code in sram, and if
> they do not match we know we have lost context and must recopy the
> functions to the previous address to maintain PM functionality.
>
> Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
> Signed-off-by: Keerthy <j-keerthy@ti.com>
> ---
> drivers/memory/ti-emif-pm.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/drivers/memory/ti-emif-pm.c b/drivers/memory/ti-emif-pm.c
> index 632651f..ec4a62c 100644
> --- a/drivers/memory/ti-emif-pm.c
> +++ b/drivers/memory/ti-emif-pm.c
> @@ -249,6 +249,25 @@ int ti_emif_get_mem_type(void)
> };
> MODULE_DEVICE_TABLE(of, ti_emif_of_match);
>
> +#ifdef CONFIG_PM_SLEEP
> +static int ti_emif_resume(struct device *dev)
> +{
> + unsigned long tmp =
> + __raw_readl((void *)emif_instance->ti_emif_sram_virt);
> +
> + /*
> + * Check to see if what we are copying is already present in the
> + * first byte at the destination, only copy if it is not which
> + * indicates we have lost context and sram no longer contains
> + * the PM code
> + */
> + if (tmp != ti_emif_sram)
> + ti_emif_push_sram(dev, emif_instance);
> +
> + return 0;
> +}
> +#endif /* CONFIG_PM_SLEEP */
Instead of this indirect method , why can't just check the previous
deep sleep mode and based on that do copy or not. EMIF power status
register should have something like that ?
Another minor point is even though there is nothing to do in suspend,
might be good to have a callback with comment that nothing to do with
some explanation why not. Don't have strong preference but may for
better readability.
Regards,
Santosh
WARNING: multiple messages have this Message-ID (diff)
From: "santosh.shilimkar@oracle.com" <santosh.shilimkar@oracle.com>
To: Keerthy <j-keerthy@ti.com>,
linus.walleij@linaro.org, grygorii.strashko@ti.com,
tony@atomide.com
Cc: d-gerlach@ti.com, linux-kernel@vger.kernel.org, t-kristo@ti.com,
Russ.Dill@ti.com, haojian.zhuang@linaro.org, ssantosh@kernel.org,
linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 01/14] memory: ti-emif-sram: Add resume function to recopy sram code
Date: Thu, 12 Apr 2018 10:44:10 -0600 [thread overview]
Message-ID: <31688cf4-b6ca-e7ce-3407-46262006b38f@oracle.com> (raw)
In-Reply-To: <1523505239-16229-2-git-send-email-j-keerthy@ti.com>
On 4/11/18 9:53 PM, Keerthy wrote:
> From: Dave Gerlach <d-gerlach@ti.com>
>
> After an RTC+DDR cycle we lose sram context so emif pm functions present
> in sram are lost. We can check if the first byte of the original
> code in DDR contains the same first byte as the code in sram, and if
> they do not match we know we have lost context and must recopy the
> functions to the previous address to maintain PM functionality.
>
> Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
> Signed-off-by: Keerthy <j-keerthy@ti.com>
> ---
> drivers/memory/ti-emif-pm.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/drivers/memory/ti-emif-pm.c b/drivers/memory/ti-emif-pm.c
> index 632651f..ec4a62c 100644
> --- a/drivers/memory/ti-emif-pm.c
> +++ b/drivers/memory/ti-emif-pm.c
> @@ -249,6 +249,25 @@ int ti_emif_get_mem_type(void)
> };
> MODULE_DEVICE_TABLE(of, ti_emif_of_match);
>
> +#ifdef CONFIG_PM_SLEEP
> +static int ti_emif_resume(struct device *dev)
> +{
> + unsigned long tmp =
> + __raw_readl((void *)emif_instance->ti_emif_sram_virt);
> +
> + /*
> + * Check to see if what we are copying is already present in the
> + * first byte at the destination, only copy if it is not which
> + * indicates we have lost context and sram no longer contains
> + * the PM code
> + */
> + if (tmp != ti_emif_sram)
> + ti_emif_push_sram(dev, emif_instance);
> +
> + return 0;
> +}
> +#endif /* CONFIG_PM_SLEEP */
Instead of this indirect method , why can't just check the previous
deep sleep mode and based on that do copy or not. EMIF power status
register should have something like that ?
Another minor point is even though there is nothing to do in suspend,
might be good to have a callback with comment that nothing to do with
some explanation why not. Don't have strong preference but may for
better readability.
Regards,
Santosh
WARNING: multiple messages have this Message-ID (diff)
From: santosh.shilimkar@oracle.com (santosh.shilimkar at oracle.com)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 01/14] memory: ti-emif-sram: Add resume function to recopy sram code
Date: Thu, 12 Apr 2018 10:44:10 -0600 [thread overview]
Message-ID: <31688cf4-b6ca-e7ce-3407-46262006b38f@oracle.com> (raw)
In-Reply-To: <1523505239-16229-2-git-send-email-j-keerthy@ti.com>
On 4/11/18 9:53 PM, Keerthy wrote:
> From: Dave Gerlach <d-gerlach@ti.com>
>
> After an RTC+DDR cycle we lose sram context so emif pm functions present
> in sram are lost. We can check if the first byte of the original
> code in DDR contains the same first byte as the code in sram, and if
> they do not match we know we have lost context and must recopy the
> functions to the previous address to maintain PM functionality.
>
> Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
> Signed-off-by: Keerthy <j-keerthy@ti.com>
> ---
> drivers/memory/ti-emif-pm.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/drivers/memory/ti-emif-pm.c b/drivers/memory/ti-emif-pm.c
> index 632651f..ec4a62c 100644
> --- a/drivers/memory/ti-emif-pm.c
> +++ b/drivers/memory/ti-emif-pm.c
> @@ -249,6 +249,25 @@ int ti_emif_get_mem_type(void)
> };
> MODULE_DEVICE_TABLE(of, ti_emif_of_match);
>
> +#ifdef CONFIG_PM_SLEEP
> +static int ti_emif_resume(struct device *dev)
> +{
> + unsigned long tmp =
> + __raw_readl((void *)emif_instance->ti_emif_sram_virt);
> +
> + /*
> + * Check to see if what we are copying is already present in the
> + * first byte at the destination, only copy if it is not which
> + * indicates we have lost context and sram no longer contains
> + * the PM code
> + */
> + if (tmp != ti_emif_sram)
> + ti_emif_push_sram(dev, emif_instance);
> +
> + return 0;
> +}
> +#endif /* CONFIG_PM_SLEEP */
Instead of this indirect method , why can't just check the previous
deep sleep mode and based on that do copy or not. EMIF power status
register should have something like that ?
Another minor point is even though there is nothing to do in suspend,
might be good to have a callback with comment that nothing to do with
some explanation why not. Don't have strong preference but may for
better readability.
Regards,
Santosh
next prev parent reply other threads:[~2018-04-12 16:44 UTC|newest]
Thread overview: 85+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-12 3:53 [PATCH 00/14] arm: OMAP: AM437X: Save restores patches for rtc mode with DDR In self-refresh Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` [PATCH 01/14] memory: ti-emif-sram: Add resume function to recopy sram code Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 16:44 ` santosh.shilimkar [this message]
2018-04-12 16:44 ` santosh.shilimkar at oracle.com
2018-04-12 16:44 ` santosh.shilimkar
2018-04-16 10:20 ` Keerthy
2018-04-16 10:20 ` Keerthy
2018-04-16 10:20 ` Keerthy
2018-04-16 10:29 ` Keerthy
2018-04-16 10:29 ` Keerthy
2018-04-16 10:29 ` Keerthy
2018-05-23 8:47 ` Keerthy
2018-05-23 8:47 ` Keerthy
2018-05-23 8:47 ` Keerthy
2018-05-23 16:42 ` Santosh Shilimkar
2018-05-23 16:42 ` Santosh Shilimkar
2018-04-12 3:53 ` [PATCH 02/14] ARM: OMAP2: Add functions to save and restore clockdomain context en-masse Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` [PATCH 03/14] ARM: OMAP2+: omap_hwmod: Introduce HWMOD_NEEDS_REIDLE Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 14:34 ` Tony Lindgren
2018-04-12 14:34 ` Tony Lindgren
2018-04-12 3:53 ` [PATCH 04/14] ARM: OMAP2: Add functions to save and restore omap hwmod context en-masse Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` [PATCH 05/14] ARM: OMAP2: Add functions to save and restore powerdomain context Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 14:37 ` Tony Lindgren
2018-04-12 14:37 ` Tony Lindgren
2018-04-12 3:53 ` [PATCH 06/14] ARM: AM33XX: Add functions to save/restore am33xx control registers Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` [PATCH 07/14] ARM: AM43XX: Add functions to save/restore am43xx " Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` [PATCH 08/14] ARM: OMAP2: Add functions to save and restore pinctrl context Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 14:16 ` Tony Lindgren
2018-04-12 14:16 ` Tony Lindgren
2018-04-13 6:16 ` Keerthy
2018-04-13 6:16 ` Keerthy
2018-04-13 6:16 ` Keerthy
2018-04-12 3:53 ` [PATCH 09/14] ARM: OMAP2: Drop the concept of certain power domains not being able to lose context Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` [PATCH 10/14] gpio: omap: Drop the concept of gpio banks " Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 14:22 ` Tony Lindgren
2018-04-12 14:22 ` Tony Lindgren
2018-04-12 20:10 ` Grygorii Strashko
2018-04-12 20:10 ` Grygorii Strashko
2018-04-12 20:10 ` Grygorii Strashko
2018-04-12 3:53 ` [PATCH 11/14] gpio: omap: Restore power_mode configuration at resume time Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 14:39 ` Tony Lindgren
2018-04-12 14:39 ` Tony Lindgren
2018-04-12 20:02 ` Grygorii Strashko
2018-04-12 20:02 ` Grygorii Strashko
2018-04-12 20:02 ` Grygorii Strashko
2018-04-12 3:53 ` [PATCH 12/14] OMAP: CLK: CLKSRC: Add suspend resume hooks Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 14:27 ` Tony Lindgren
2018-04-12 14:27 ` Tony Lindgren
2018-05-22 7:57 ` Keerthy
2018-05-22 7:57 ` Keerthy
2018-05-22 7:57 ` Keerthy
2018-05-22 13:39 ` Tony Lindgren
2018-05-22 13:39 ` Tony Lindgren
2018-04-12 3:53 ` [PATCH 13/14] ARM: hwmod: RTC: Don't assume lock/unlock will be called with irq enabled Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` [PATCH 14/14] ARM: OMAP2+: prm44xx: Introduce context save/restore for am43 PRCM IO Keerthy
2018-04-12 3:53 ` Keerthy
2018-04-12 3:53 ` Keerthy
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