[PATCH 4/4] PM / shmobile: Specify device latencies for Mackerel devices directly

From: Rafael J. Wysocki
Date: Wed Aug 08 2012 - 05:01:47 EST



The results of adaptive latency computations in
GENPD_DEV_TIMED_CALLBACK() show that the start/stop and save/restore
state latencies of all devices on the Mackerel board I have tried are
a little below 250 us. Therefore, if the 250 us is used as the
common initial value of the latency fields in struct gpd_timing_data
for all devices on Mackerel, the latency values will never have to
change at run time and there won't be any overhead related to
re-computation of the corresponding PM QoS data.

Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
---
arch/arm/mach-shmobile/board-mackerel.c | 31 +++++++++++++++++++------------
1 file changed, 19 insertions(+), 12 deletions(-)

Index: linux/arch/arm/mach-shmobile/board-mackerel.c
===================================================================
--- linux.orig/arch/arm/mach-shmobile/board-mackerel.c
+++ linux/arch/arm/mach-shmobile/board-mackerel.c
@@ -1407,8 +1407,15 @@ static struct i2c_board_info i2c1_device
#define GPIO_PORT168CR 0xE60520A8
#define SRCR4 0xe61580bc
#define USCCR1 0xE6058144
+#define DEV_LATENCY_NS 250000
static void __init mackerel_init(void)
{
+ struct gpd_timing_data latencies = {
+ .stop_latency_ns = DEV_LATENCY_NS,
+ .start_latency_ns = DEV_LATENCY_NS,
+ .save_state_latency_ns = DEV_LATENCY_NS,
+ .restore_state_latency_ns = DEV_LATENCY_NS,
+ };
u32 srcr4;
struct clk *clk;

@@ -1623,20 +1630,20 @@ static void __init mackerel_init(void)

platform_add_devices(mackerel_devices, ARRAY_SIZE(mackerel_devices));

- rmobile_add_device_to_domain("A4LC", &lcdc_device);
- rmobile_add_device_to_domain("A4LC", &hdmi_lcdc_device);
- rmobile_add_device_to_domain("A4LC", &meram_device);
- rmobile_add_device_to_domain("A4MP", &fsi_device);
- rmobile_add_device_to_domain("A3SP", &usbhs0_device);
- rmobile_add_device_to_domain("A3SP", &usbhs1_device);
- rmobile_add_device_to_domain("A3SP", &nand_flash_device);
- rmobile_add_device_to_domain("A3SP", &sh_mmcif_device);
- rmobile_add_device_to_domain("A3SP", &sdhi0_device);
+ rmobile_add_device_to_domain_td("A4LC", &lcdc_device, &latencies);
+ rmobile_add_device_to_domain_td("A4LC", &hdmi_lcdc_device, &latencies);
+ rmobile_add_device_to_domain_td("A4LC", &meram_device, &latencies);
+ rmobile_add_device_to_domain_td("A4MP", &fsi_device, &latencies);
+ rmobile_add_device_to_domain_td("A3SP", &usbhs0_device, &latencies);
+ rmobile_add_device_to_domain_td("A3SP", &usbhs1_device, &latencies);
+ rmobile_add_device_to_domain_td("A3SP", &nand_flash_device, &latencies);
+ rmobile_add_device_to_domain_td("A3SP", &sh_mmcif_device, &latencies);
+ rmobile_add_device_to_domain_td("A3SP", &sdhi0_device, &latencies);
#if !defined(CONFIG_MMC_SH_MMCIF) && !defined(CONFIG_MMC_SH_MMCIF_MODULE)
- rmobile_add_device_to_domain("A3SP", &sdhi1_device);
+ rmobile_add_device_to_domain_td("A3SP", &sdhi1_device, &latencies);
#endif
- rmobile_add_device_to_domain("A3SP", &sdhi2_device);
- rmobile_add_device_to_domain("A4R", &ceu_device);
+ rmobile_add_device_to_domain_td("A3SP", &sdhi2_device, &latencies);
+ rmobile_add_device_to_domain_td("A4R", &ceu_device, &latencies);

hdmi_init_pm_clock();
sh7372_pm_init();

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