| Message ID | 20170620151855.19399-15-paul@crapouillou.net (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
Hi Paul, Maarten, On 20.06.2017 17:18, Paul Cercueil wrote: > From: Maarten ter Huurne <maarten@treewalker.org> > > We have seen MMC DMA transfers read corrupted data from SDRAM when > a burst interval ends at physical address 0x10000000. To avoid this > problem, we remove the final page of low memory from the memory map. > > Signed-off-by: Maarten ter Huurne <maarten@treewalker.org> > --- > arch/mips/jz4740/setup.c | 24 ++++++++++++++++++++++++ > arch/mips/kernel/setup.c | 8 ++++++++ > 2 files changed, 32 insertions(+) > > v2: No change > > diff --git a/arch/mips/jz4740/setup.c b/arch/mips/jz4740/setup.c > index afd84ee966e8..6948b133a15d 100644 > --- a/arch/mips/jz4740/setup.c > +++ b/arch/mips/jz4740/setup.c > @@ -23,6 +23,7 @@ > > #include <asm/bootinfo.h> > #include <asm/mips_machine.h> > +#include <asm/page.h> > #include <asm/prom.h> > > #include <asm/mach-jz4740/base.h> > @@ -102,6 +103,29 @@ void __init arch_init_irq(void) > irqchip_init(); > } > > +/* > + * We have seen MMC DMA transfers read corrupted data from SDRAM when a burst > + * interval ends at physical address 0x10000000. To avoid this problem, we > + * remove the final page of low memory from the memory map. > + */ > +void __init jz4770_reserve_unsafe_for_dma(void) > +{ > + int i; > + > + for (i = 0; i < boot_mem_map.nr_map; i++) { > + struct boot_mem_map_entry *entry = boot_mem_map.map + i; > + > + if (entry->type != BOOT_MEM_RAM) > + continue; > + > + if (entry->addr + entry->size != 0x10000000) > + continue; > + > + entry->size -= PAGE_SIZE; > + break; > + } > +} > + > static int __init jz4740_machine_setup(void) > { > mips_machine_setup(); > diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c > index 89785600fde4..cccfd7ba89fe 100644 > --- a/arch/mips/kernel/setup.c > +++ b/arch/mips/kernel/setup.c > @@ -838,6 +838,14 @@ static void __init arch_mem_init(char **cmdline_p) > > parse_early_param(); > > +#ifdef CONFIG_MACH_JZ4770 > + if (current_cpu_type() == CPU_JZRISC && > + mips_machtype == MACH_INGENIC_JZ4770) { > + extern void __init jz4770_reserve_unsafe_for_dma(void); > + jz4770_reserve_unsafe_for_dma(); > + } > +#endif > + This part doesn't look good in the platform-agnostic code ... is there a reason why you wouldn't do that from within plat_mem_setup()? > if (usermem) { > pr_info("User-defined physical RAM map:\n"); > print_memory_map(); > Marcin -- To unsubscribe from this list: send the line "unsubscribe linux-clk" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi, Le 2017-06-22 09:21, Marcin Nowakowski a écrit : > Hi Paul, Maarten, > > On 20.06.2017 17:18, Paul Cercueil wrote: >> From: Maarten ter Huurne <maarten@treewalker.org> >> >> We have seen MMC DMA transfers read corrupted data from SDRAM when >> a burst interval ends at physical address 0x10000000. To avoid this >> problem, we remove the final page of low memory from the memory map. >> >> Signed-off-by: Maarten ter Huurne <maarten@treewalker.org> >> --- >> arch/mips/jz4740/setup.c | 24 ++++++++++++++++++++++++ >> arch/mips/kernel/setup.c | 8 ++++++++ >> 2 files changed, 32 insertions(+) >> >> v2: No change >> >> diff --git a/arch/mips/jz4740/setup.c b/arch/mips/jz4740/setup.c >> index afd84ee966e8..6948b133a15d 100644 >> --- a/arch/mips/jz4740/setup.c >> +++ b/arch/mips/jz4740/setup.c >> @@ -23,6 +23,7 @@ >> #include <asm/bootinfo.h> >> #include <asm/mips_machine.h> >> +#include <asm/page.h> >> #include <asm/prom.h> >> #include <asm/mach-jz4740/base.h> >> @@ -102,6 +103,29 @@ void __init arch_init_irq(void) >> irqchip_init(); >> } >> +/* >> + * We have seen MMC DMA transfers read corrupted data from SDRAM when >> a burst >> + * interval ends at physical address 0x10000000. To avoid this >> problem, we >> + * remove the final page of low memory from the memory map. >> + */ >> +void __init jz4770_reserve_unsafe_for_dma(void) >> +{ >> + int i; >> + >> + for (i = 0; i < boot_mem_map.nr_map; i++) { >> + struct boot_mem_map_entry *entry = boot_mem_map.map + i; >> + >> + if (entry->type != BOOT_MEM_RAM) >> + continue; >> + >> + if (entry->addr + entry->size != 0x10000000) >> + continue; >> + >> + entry->size -= PAGE_SIZE; >> + break; >> + } >> +} >> + >> static int __init jz4740_machine_setup(void) >> { >> mips_machine_setup(); >> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c >> index 89785600fde4..cccfd7ba89fe 100644 >> --- a/arch/mips/kernel/setup.c >> +++ b/arch/mips/kernel/setup.c >> @@ -838,6 +838,14 @@ static void __init arch_mem_init(char >> **cmdline_p) >> parse_early_param(); >> +#ifdef CONFIG_MACH_JZ4770 >> + if (current_cpu_type() == CPU_JZRISC && >> + mips_machtype == MACH_INGENIC_JZ4770) { >> + extern void __init jz4770_reserve_unsafe_for_dma(void); >> + jz4770_reserve_unsafe_for_dma(); >> + } >> +#endif >> + > > This part doesn't look good in the platform-agnostic code ... is there > a reason why you wouldn't do that from within plat_mem_setup()? > I agree, but, doing it in plat_mem_setup() is too early, as the 'boot mem map' hasn't been initialized yet then... >> if (usermem) { >> pr_info("User-defined physical RAM map:\n"); >> print_memory_map(); >> > > > Marcin -- To unsubscribe from this list: send the line "unsubscribe linux-clk" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/mips/jz4740/setup.c b/arch/mips/jz4740/setup.c index afd84ee966e8..6948b133a15d 100644 --- a/arch/mips/jz4740/setup.c +++ b/arch/mips/jz4740/setup.c @@ -23,6 +23,7 @@ #include <asm/bootinfo.h> #include <asm/mips_machine.h> +#include <asm/page.h> #include <asm/prom.h> #include <asm/mach-jz4740/base.h> @@ -102,6 +103,29 @@ void __init arch_init_irq(void) irqchip_init(); } +/* + * We have seen MMC DMA transfers read corrupted data from SDRAM when a burst + * interval ends at physical address 0x10000000. To avoid this problem, we + * remove the final page of low memory from the memory map. + */ +void __init jz4770_reserve_unsafe_for_dma(void) +{ + int i; + + for (i = 0; i < boot_mem_map.nr_map; i++) { + struct boot_mem_map_entry *entry = boot_mem_map.map + i; + + if (entry->type != BOOT_MEM_RAM) + continue; + + if (entry->addr + entry->size != 0x10000000) + continue; + + entry->size -= PAGE_SIZE; + break; + } +} + static int __init jz4740_machine_setup(void) { mips_machine_setup(); diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index 89785600fde4..cccfd7ba89fe 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -838,6 +838,14 @@ static void __init arch_mem_init(char **cmdline_p) parse_early_param(); +#ifdef CONFIG_MACH_JZ4770 + if (current_cpu_type() == CPU_JZRISC && + mips_machtype == MACH_INGENIC_JZ4770) { + extern void __init jz4770_reserve_unsafe_for_dma(void); + jz4770_reserve_unsafe_for_dma(); + } +#endif + if (usermem) { pr_info("User-defined physical RAM map:\n"); print_memory_map();