@@ -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);
@@ -80,6 +81,12 @@ static void do_hw_reset(void)
OWER = OWER_WME;
OSSR = OSSR_M3;
OSMR3 = OSCR + 368640; /* ... in 100 ms */
+ /*
+ * 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(char mode, const char *cmd)
@@ -103,4 +110,3 @@ void pxa_restart(char mode, const char *cmd)
break;
}
}
-
This is a note to let you know that I have just added a patch titled ARM: pxa: prevent PXA270 occasional reboot freezes to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 3d8dfe8f2e5a28ffde5be6b39b0a594da7b80584 Mon Sep 17 00:00:00 2001 From: Sergei Ianovich <ynvich@gmail.com> Date: Tue, 10 Dec 2013 08:39:15 +0400 Subject: ARM: pxa: prevent PXA270 occasional reboot freezes commit ff88b4724fde18056a4c539f7327389aec0f4c2d upstream. 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 <ynvich@gmail.com> Tested-by: Marek Vasut <marex@denx.de> Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com> Signed-off-by: Olof Johansson <olof@lixom.net> [ luis: backported to 3.5: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- arch/arm/mach-pxa/reset.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) -- 1.8.3.2