[U-Boot] [PATCH 1/2] mips: mt76xx: Flush d-cache in arch_misc_init() to solve d-cache issues

[Stefan Roese]

It has been noticed, that sometimes the d-cache is not in a
"clean-state" when U-Boot is running on MT7688. This was detected when
using the ethernet driver (which uses d-cache) and a TFTP command does
not complete. Flushing the complete d-cache (again?) here seems to fix
this issue.

Signed-off-by: Stefan Roese <sr at denx.de>
Cc: Daniel Schwierzeck <daniel.schwierzeck at gmail.com>
---
 arch/mips/Kconfig           |  2 +-
 arch/mips/mach-mt7620/cpu.c | 14 +++++++++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 1b1b1d7d00..355d3b4d91 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -79,7 +79,7 @@ config ARCH_MT7620
 	select DM_SERIAL
 	imply DM_SPI
 	imply DM_SPI_FLASH
-	select ARCH_MISC_INIT if WATCHDOG
+	select ARCH_MISC_INIT
 	select MIPS_TUNE_24KC
 	select OF_CONTROL
 	select ROM_EXCEPTION_VECTORS
diff --git a/arch/mips/mach-mt7620/cpu.c b/arch/mips/mach-mt7620/cpu.c
index 87cc973b75..9e0ca716f7 100644
--- a/arch/mips/mach-mt7620/cpu.c
+++ b/arch/mips/mach-mt7620/cpu.c
@@ -89,9 +89,21 @@ void watchdog_reset(void)
 		wdt_reset(watchdog_dev);
 	}
 }
+#endif
 
 int arch_misc_init(void)
 {
+	/*
+	 * It has been noticed, that sometimes the d-cache is not in a
+	 * "clean-state" when U-Boot is running on MT7688. This was
+	 * detected when using the ethernet driver (which uses d-cache)
+	 * and a TFTP command does not complete. Flushing the complete
+	 * d-cache (again?) here seems to fix this issue.
+	 */
+	flush_dcache_range(gd->bd->bi_memstart,
+			   gd->bd->bi_memstart + gd->ram_size - 1);
+
+#ifdef CONFIG_WATCHDOG
 	/* Init watchdog */
 	if (uclass_get_device_by_seq(UCLASS_WDT, 0, &watchdog_dev)) {
 		debug("Watchdog: Not found by seq!\n");
@@ -103,7 +115,7 @@ int arch_misc_init(void)
 
 	wdt_start(watchdog_dev, 60000, 0);	/* 60 seconds */
 	printf("Watchdog: Started\n");
+#endif
 
 	return 0;
 }
-#endif
-- 
2.20.1