4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jayachandran C <jnair@xxxxxxxxxxxxxxxxxx> [ 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 <jnair@xxxxxxxxxxxxxxxxxx> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Wim Van Sebroeck <wim@xxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/watchdog/sbsa_gwdt.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/watchdog/sbsa_gwdt.c +++ b/drivers/watchdog/sbsa_gwdt.c @@ -50,6 +50,7 @@ */ #include <linux/io.h> +#include <linux/io-64-nonatomic-lo-hi.h> #include <linux/interrupt.h> #include <linux/module.h> #include <linux/moduleparam.h> @@ -159,7 +160,7 @@ static unsigned int sbsa_gwdt_get_timele !(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);
