Re: [Linaro-acpi] [RESEND PATCH v4 5/5] clocksource: add memory-mapped timer support in arm_arch_timer.c

On Fri, 18 Mar 2016, fu.wei@linaro.org wrote:

+static u32 __init arch_timer_mem_cnttidr(struct acpi_gtdt_timer_block *gt_block) +{

• phys_addr_t cntctlbase_phy;
• void __iomem *cntctlbase;
• u32 cnttidr;
• cntctlbase_phy = (phys_addr_t)gtdt_gt_cntctlbase(gt_block);
• if (!cntctlbase_phy) {

• pr_err("Can't find CNTCTLBase.\n");
  

• return 0;
  

• }
• /*

• * According to ARMv8 Architecture Reference Manual(ARM),
  

• * the size of CNTCTLBase frame of memory-mapped timer
  

• * is SZ_4K(Offset 0x000 – 0xFFF).
  

• */
  

• cntctlbase = ioremap(cntctlbase_phy, SZ_4K);
• if (!cntctlbase) {

• pr_err("Can't map CNTCTLBase\n");
  

• return 0;
  

• }

Why are you continuing when you can't find a base address or the remap fails?

• /*

• * Get Generic Timer Counter-timer Timer ID Register
  

• * for Virtual Timer Capability info
  

• */
  

• cnttidr = arch_timer_mem_cnttidr(gt_block);

Thanks,

tglx