[PATCH 2/2] power/reset: at91-poweroff: timely shitdown LPDDR memories
From: Alexandre Belloni <hidden>
Date: 2016-10-13 11:10:34
Also in:
linux-pm, lkml
From: Alexandre Belloni <hidden>
Date: 2016-10-13 11:10:34
Also in:
linux-pm, lkml
On 12/10/2016 at 14:48:27 +0200, Jean-Jacques Hiblot wrote :
quoted
+static void at91_lpddr_poweroff(void) +{ + asm volatile( + /* Align to cache lines */ + ".balign 32\n\t" + + " ldr r6, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"At first sight, it looks useless. I assume it's used to preload the TLB before the LPDDR is turned off. A comment to explain why this line is useful would prevent its removal.
Yes, this is the case. I can add a comment. Anyway, I would prefer the whole thing to run from SRAM, as a PIE instead of relying on the cache.
quoted
+ ddr_type = readl(mpddrc_base + AT91_DDRSDRC_MDR) & AT91_DDRSDRC_MD; + if ((ddr_type == AT91_DDRSDRC_MD_LPDDR2) || + (ddr_type == AT91_DDRSDRC_MD_LPDDR3))Souldn't there be something like "pm_power_off = at91_lpddr_poweroff;" here ?
Indeed -- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com