On Tuesday, December 10, 2013 at 11:48:59 AM, Daniel Mack wrote: > On 12/10/2013 09:43 AM, Haojian Zhuang wrote: > > On 12/10/2013 12:39 PM, Sergei Ianovich wrote: > >> Erratum 71 of PXA270M Processor Family Specification Update > >> (April 19, 2010) explains that watchdog reset time is just > >> 8us insead of 10ms in EMTS. > >> > >> If SDRAM is not reset, it causes memory bus congestion and > >> the device hangs. We put SDRAM in selfresh mode before watchdog > >> reset, removing potential freezes. > >> > >> Without this patch PXA270-based ICP DAS LP-8x4x hangs after up to 40 > >> reboots. With this patch it has successfully rebooted 500 times. > >> > >> Signed-off-by: Sergei Ianovich <ynv...@gmail.com> > >> --- > >> > >> arch/arm/mach-pxa/reset.c | 8 +++++++- > >> 1 file changed, 7 insertions(+), 1 deletion(-) > >> > >> diff --git a/arch/arm/mach-pxa/reset.c b/arch/arm/mach-pxa/reset.c > >> index 0d5dd64..263b152 100644 > >> --- a/arch/arm/mach-pxa/reset.c > >> +++ b/arch/arm/mach-pxa/reset.c > >> @@ -13,6 +13,7 @@ > >> > >> #include <mach/regs-ost.h> > >> #include <mach/reset.h> > >> > >> +#include <mach/smemc.h> > >> > >> unsigned int reset_status; > >> EXPORT_SYMBOL(reset_status); > >> > >> @@ -81,6 +82,12 @@ static void do_hw_reset(void) > >> > >> writel_relaxed(OSSR_M3, OSSR); > >> /* ... in 100 ms */ > >> writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3); > >> > >> + /* > >> + * SDRAM hangs on watchdog reset on Marvell PXA270 (erratum 71) > >> + * we put SDRAM into self-refresh to prevent that > >> + */ > >> + while (1) > >> + writel_relaxed(MDREFR_SLFRSH, MDREFR); > >> > >> } > >> > >> void pxa_restart(enum reboot_mode mode, const char *cmd) > >> > >> @@ -104,4 +111,3 @@ void pxa_restart(enum reboot_mode mode, const char > >> *cmd) > >> > >> break; > >> > >> } > >> > >> } > >> > >> - > > > > Hi Daniel/Marek/Igor, > > > > Could you help to try this patch? I'm lack of PXA27x board. > > I don't have any either right now ...
On VPAC270 Tested-by: Marek Vasut <ma...@denx.de> Best regards, Marek Vasut -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
