[PATCH 5.14 072/151] MIPS: Revert "add support for buggy MT7621S core detection"

Greg Kroah-Hartman
2021-10-11T14:07:40Z

From: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>

[ Upstream commit 740da9d7ca4e25f5d87db9f80d75432681b61305 ]

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: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Acked-by: Greg Ungerer <gerg@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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