[PATCH] LoongArch: Use a fallback CPU model when IOCSR-based model probing fails

[Yao Zi <ziyao@disroot.org>]

Reading vendor and cpuname IOCSRs yields 0x258000fff00 instead of
human-readable model strings on Loongson 2K0300 SoC, which messes up
format of /proc/cpuinfo since it represents as an empty string.

Let's consider IOCSR-based model probing fails if the result model is an
empty string. A fallback model name is set in such cases.

Signed-off-by: Yao Zi <ziyao@disroot.org>
---
 arch/loongarch/kernel/cpu-probe.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/loongarch/kernel/cpu-probe.c b/arch/loongarch/kernel/cpu-probe.c
index fedaa67cde41..785513d43696 100644
--- a/arch/loongarch/kernel/cpu-probe.c
+++ b/arch/loongarch/kernel/cpu-probe.c
@@ -270,12 +270,13 @@ static inline void cpu_probe_loongson(struct cpuinfo_loongarch *c, unsigned int
 	if (!cpu_has_iocsr)
 		return;
 
-	if (!__cpu_full_name[cpu])
-		__cpu_full_name[cpu] = cpu_full_name;
-
 	*vendor = iocsr_read64(LOONGARCH_IOCSR_VENDOR);
 	*cpuname = iocsr_read64(LOONGARCH_IOCSR_CPUNAME);
 
+	if (!__cpu_full_name[cpu])
+		__cpu_full_name[cpu] = cpu_full_name[0] ? cpu_full_name :
+							  "Loongson-Unknown";
+
 	config = iocsr_read32(LOONGARCH_IOCSR_FEATURES);
 	if (config & IOCSRF_CSRIPI)
 		c->options |= LOONGARCH_CPU_CSRIPI;
-- 
2.49.0