[PATCH] MIPS: Revert "add support for buggy MT7621S core detection"

[PATCH] MIPS: Revert "add support for buggy MT7621S core detection"

[Ilya Lipnitskiy]

This reverts commit 6decd1aad15f56b169217789630a0098b496de0e. CPULAUNCH
register is not set properly by some bootloaders, causing a regression
until a bootloader change is made, which is hard if not impossible on
some embedded devices. Revert the change until a more robust core
detection mechanism that works on MT7621S routers such as Netgear R6220
as well as platforms like Digi EX15 can be made.

Link: https://lore.kernel.org/lkml/4d9e3b39-7caa-d372-5d7b-42dcec36fec7@kernel.org
Fixes: 6decd1aad15f ("MIPS: add support for buggy MT7621S core detection")
Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
---
 arch/mips/include/asm/mips-cps.h | 23 +----------------------
 1 file changed, 1 insertion(+), 22 deletions(-)

diff --git a/arch/mips/include/asm/mips-cps.h b/arch/mips/include/asm/mips-cps.h
index 35fb8ee6dd33..fd43d876892e 100644
--- a/arch/mips/include/asm/mips-cps.h
+++ b/arch/mips/include/asm/mips-cps.h
@@ -10,8 +10,6 @@
 #include <linux/io.h>
 #include <linux/types.h>
 
-#include <asm/mips-boards/launch.h>
-
 extern unsigned long __cps_access_bad_size(void)
 	__compiletime_error("Bad size for CPS accessor");
 
@@ -167,30 +165,11 @@ static inline uint64_t mips_cps_cluster_config(unsigned int cluster)
  */
 static inline unsigned int mips_cps_numcores(unsigned int cluster)
 {
-	unsigned int ncores;
-
 	if (!mips_cm_present())
 		return 0;
 
 	/* Add one before masking to handle 0xff indicating no cores */
-	ncores = (mips_cps_cluster_config(cluster) + 1) & CM_GCR_CONFIG_PCORES;
-
-	if (IS_ENABLED(CONFIG_SOC_MT7621)) {
-		struct cpulaunch *launch;
-
-		/*
-		 * Ralink MT7621S SoC is single core, but the GCR_CONFIG method
-		 * always reports 2 cores. Check the second core's LAUNCH_FREADY
-		 * flag to detect if the second core is missing. This method
-		 * only works before the core has been started.
-		 */
-		launch = (struct cpulaunch *)CKSEG0ADDR(CPULAUNCH);
-		launch += 2; /* MT7621 has 2 VPEs per core */
-		if (!(launch->flags & LAUNCH_FREADY))
-			ncores = 1;
-	}
-
-	return ncores;
+	return (mips_cps_cluster_config(cluster) + 1) & CM_GCR_CONFIG_PCORES;
 }
 
 /**
-- 
2.33.0

Re: [PATCH] MIPS: Revert "add support for buggy MT7621S core detection"

[Sergio Paracuellos]

On Thu, Sep 30, 2021 at 6:58 PM Ilya Lipnitskiy
<ilya.lipnitskiy@gmail.com> wrote:
>
> This reverts commit 6decd1aad15f56b169217789630a0098b496de0e. CPULAUNCH
> register is not set properly by some bootloaders, causing a regression
> until a bootloader change is made, which is hard if not impossible on
> some embedded devices. Revert the change until a more robust core
> detection mechanism that works on MT7621S routers such as Netgear R6220
> as well as platforms like Digi EX15 can be made.
>
> Link: https://lore.kernel.org/lkml/4d9e3b39-7caa-d372-5d7b-42dcec36fec7@kernel.org
> Fixes: 6decd1aad15f ("MIPS: add support for buggy MT7621S core detection")
> Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
> ---
>  arch/mips/include/asm/mips-cps.h | 23 +----------------------
>  1 file changed, 1 insertion(+), 22 deletions(-)

Acked-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>

Thanks,
     Sergio Paracuellos
>
> diff --git a/arch/mips/include/asm/mips-cps.h b/arch/mips/include/asm/mips-cps.h
> index 35fb8ee6dd33..fd43d876892e 100644
> --- a/arch/mips/include/asm/mips-cps.h
> +++ b/arch/mips/include/asm/mips-cps.h
> @@ -10,8 +10,6 @@
>  #include <linux/io.h>
>  #include <linux/types.h>
>
> -#include <asm/mips-boards/launch.h>
> -
>  extern unsigned long __cps_access_bad_size(void)
>         __compiletime_error("Bad size for CPS accessor");
>
> @@ -167,30 +165,11 @@ static inline uint64_t mips_cps_cluster_config(unsigned int cluster)
>   */
>  static inline unsigned int mips_cps_numcores(unsigned int cluster)
>  {
> -       unsigned int ncores;
> -
>         if (!mips_cm_present())
>                 return 0;
>
>         /* Add one before masking to handle 0xff indicating no cores */
> -       ncores = (mips_cps_cluster_config(cluster) + 1) & CM_GCR_CONFIG_PCORES;
> -
> -       if (IS_ENABLED(CONFIG_SOC_MT7621)) {
> -               struct cpulaunch *launch;
> -
> -               /*
> -                * Ralink MT7621S SoC is single core, but the GCR_CONFIG method
> -                * always reports 2 cores. Check the second core's LAUNCH_FREADY
> -                * flag to detect if the second core is missing. This method
> -                * only works before the core has been started.
> -                */
> -               launch = (struct cpulaunch *)CKSEG0ADDR(CPULAUNCH);
> -               launch += 2; /* MT7621 has 2 VPEs per core */
> -               if (!(launch->flags & LAUNCH_FREADY))
> -                       ncores = 1;
> -       }
> -
> -       return ncores;
> +       return (mips_cps_cluster_config(cluster) + 1) & CM_GCR_CONFIG_PCORES;
>  }
>
>  /**
> --
> 2.33.0
>

Re: [PATCH] MIPS: Revert "add support for buggy MT7621S core detection"

[Greg Ungerer]

On 1/10/21 2:57 am, Ilya Lipnitskiy wrote:
> This reverts commit 6decd1aad15f56b169217789630a0098b496de0e. CPULAUNCH
> register is not set properly by some bootloaders, causing a regression
> until a bootloader change is made, which is hard if not impossible on
> some embedded devices. Revert the change until a more robust core
> detection mechanism that works on MT7621S routers such as Netgear R6220
> as well as platforms like Digi EX15 can be made.
> 
> Link: https://lore.kernel.org/lkml/4d9e3b39-7caa-d372-5d7b-42dcec36fec7@kernel.org
> Fixes: 6decd1aad15f ("MIPS: add support for buggy MT7621S core detection")
> Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>

Acked-by: Greg Ungerer <gerg@kernel.org>

Thanks Ilya for taking care of this.

Regards
Greg


> ---
>   arch/mips/include/asm/mips-cps.h | 23 +----------------------
>   1 file changed, 1 insertion(+), 22 deletions(-)
> 
> diff --git a/arch/mips/include/asm/mips-cps.h b/arch/mips/include/asm/mips-cps.h
> index 35fb8ee6dd33..fd43d876892e 100644
> --- a/arch/mips/include/asm/mips-cps.h
> +++ b/arch/mips/include/asm/mips-cps.h
> @@ -10,8 +10,6 @@
>   #include <linux/io.h>
>   #include <linux/types.h>
>   
> -#include <asm/mips-boards/launch.h>
> -
>   extern unsigned long __cps_access_bad_size(void)
>   	__compiletime_error("Bad size for CPS accessor");
>   
> @@ -167,30 +165,11 @@ static inline uint64_t mips_cps_cluster_config(unsigned int cluster)
>    */
>   static inline unsigned int mips_cps_numcores(unsigned int cluster)
>   {
> -	unsigned int ncores;
> -
>   	if (!mips_cm_present())
>   		return 0;
>   
>   	/* Add one before masking to handle 0xff indicating no cores */
> -	ncores = (mips_cps_cluster_config(cluster) + 1) & CM_GCR_CONFIG_PCORES;
> -
> -	if (IS_ENABLED(CONFIG_SOC_MT7621)) {
> -		struct cpulaunch *launch;
> -
> -		/*
> -		 * Ralink MT7621S SoC is single core, but the GCR_CONFIG method
> -		 * always reports 2 cores. Check the second core's LAUNCH_FREADY
> -		 * flag to detect if the second core is missing. This method
> -		 * only works before the core has been started.
> -		 */
> -		launch = (struct cpulaunch *)CKSEG0ADDR(CPULAUNCH);
> -		launch += 2; /* MT7621 has 2 VPEs per core */
> -		if (!(launch->flags & LAUNCH_FREADY))
> -			ncores = 1;
> -	}
> -
> -	return ncores;
> +	return (mips_cps_cluster_config(cluster) + 1) & CM_GCR_CONFIG_PCORES;
>   }
>   
>   /**
> 

Re: [PATCH] MIPS: Revert "add support for buggy MT7621S core detection"

[Thomas Bogendoerfer]

On Thu, Sep 30, 2021 at 09:57:41AM -0700, Ilya Lipnitskiy wrote:
> This reverts commit 6decd1aad15f56b169217789630a0098b496de0e. CPULAUNCH
> register is not set properly by some bootloaders, causing a regression
> until a bootloader change is made, which is hard if not impossible on
> some embedded devices. Revert the change until a more robust core
> detection mechanism that works on MT7621S routers such as Netgear R6220
> as well as platforms like Digi EX15 can be made.
> 
> Link: https://lore.kernel.org/lkml/4d9e3b39-7caa-d372-5d7b-42dcec36fec7@kernel.org
> Fixes: 6decd1aad15f ("MIPS: add support for buggy MT7621S core detection")
> Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
> ---
>  arch/mips/include/asm/mips-cps.h | 23 +----------------------
>  1 file changed, 1 insertion(+), 22 deletions(-)

applied to mips-fixes.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]