4.9-stable review patch. If anyone has any objections, please let me know.
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From: Jayachandran C jnair@caviumnetworks.com
[ 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@caviumnetworks.com Reviewed-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Wim Van Sebroeck wim@iguana.be Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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);