On 06/04/2017 at 18:45:39 +0100, Ben Hutchings wrote: > On Thu, 2017-04-06 at 10:38 +0200, Greg Kroah-Hartman wrote: > > 4.4-stable review patch. If anyone has any objections, please let me know. > > > > ------------------ > > > > From: Alexandre Belloni <[email protected]> > > > > commit 0b0408745e7ff24757cbfd571d69026c0ddb803c upstream. > > > > LPDDR memories can only handle up to 400 uncontrolled power off. Ensure the > > proper power off sequence is used before shutting down the platform. > > > > Signed-off-by: Alexandre Belloni <[email protected]> > > Signed-off-by: Sebastian Reichel <[email protected]> > > Signed-off-by: Greg Kroah-Hartman <[email protected]> > [...] > > +static void at91_lpddr_poweroff(void) > > +{ > > + asm volatile( > > + /* Align to cache lines */ > > + ".balign 32\n\t" > > + > > + /* Ensure AT91_SHDW_CR is in the TLB by reading it */ > > + " ldr r6, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t" > > This clobbers r6... > > > + /* Power down SDRAM0 */ > > + " str %1, [%0, #" __stringify(AT91_DDRSDRC_LPR) > > "]\n\t" > > + /* Shutdown CPU */ > > + " str %3, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t" > > + > > + " b .\n\t" > > + : > > + : "r" (mpddrc_base), > > + "r" cpu_to_le32(AT91_DDRSDRC_LPDDR2_PWOFF), > > + "r" (at91_shdwc_base), > > + "r" cpu_to_le32(AT91_SHDW_KEY | AT91_SHDW_SHDW) > > + : "r0"); > [...] > > ...but the clobber list has r0. >
Indeed. However, It doesn't matter much as nothing can possibly run afterwards. -- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
