From 73ecd80bca2bab39fd926aadf2a0665ee25e026e Mon Sep 17 00:00:00 2001 From: Jayachandran C Date: Wed, 28 Feb 2018 02:52:20 -0800 Subject: [PATCH] watchdog: sbsa: use 32-bit read for WCV [ Upstream commit 93ac3deb7c220cbcec032a967220a1f109d58431 ] According to SBSA spec v3.1 section 5.3: All registers are 32 bits in size and should be accessed using 32-bit reads and writes. If an access size other than 32 bits is used then the results are IMPLEMENTATION DEFINED. [...] The Generic Watchdog is little-endian The current code uses readq to read the watchdog compare register which does a 64-bit access. This fails on ThunderX2 which does not implement 64-bit access to this register. Fix this by using lo_hi_readq() that does two 32-bit reads. Signed-off-by: Jayachandran C Reviewed-by: Guenter Roeck Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/watchdog/sbsa_gwdt.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/watchdog/sbsa_gwdt.c b/drivers/watchdog/sbsa_gwdt.c index 316c2eb122d2..e8bd9887c566 100644 --- a/drivers/watchdog/sbsa_gwdt.c +++ b/drivers/watchdog/sbsa_gwdt.c @@ -50,6 +50,7 @@ */ #include +#include #include #include #include @@ -159,7 +160,7 @@ static unsigned int sbsa_gwdt_get_timeleft(struct watchdog_device *wdd) !(readl(gwdt->control_base + SBSA_GWDT_WCS) & SBSA_GWDT_WCS_WS0)) timeleft += readl(gwdt->control_base + SBSA_GWDT_WOR); - timeleft += readq(gwdt->control_base + SBSA_GWDT_WCV) - + timeleft += lo_hi_readq(gwdt->control_base + SBSA_GWDT_WCV) - arch_counter_get_cntvct(); do_div(timeleft, gwdt->clk);