On Thu, Aug 27, 2015 at 10:14:14AM +0300, Mika Westerberg wrote: > On Thu, Aug 27, 2015 at 08:09:55PM +0530, Kasagar, Srinidhi wrote: > > On Mon, Aug 24, 2015 at 12:44:55PM +0300, Mika Westerberg wrote: > > > On Mon, Aug 24, 2015 at 10:39:21PM +0530, Kasagar, Srinidhi wrote: > > > > Ok, then we have two options: > > > > > > > > Let's drop LPSS_NO_D3_DELAY for BYT and duplicate the common devices which > > > > are shared between Braswell and BYT & keep LPSS_NO_D3_DELAY only for BSW. > > > > > > That sounds the safest option for now. > > > > > > > OR > > > > Use the cpu id to detect the platform which I believe not a good idea.. > > > > > > > > Because of few devices, I do not think it make sense to compromise on > > > > the significant reduction in the resume delay. > > > > > > I agree. > > > > Refreshed the patch (below) affecting BSW platform alone. > > > > But this does not solve your earlier concern on Broadwell which > > shares the same acpi ids.. > > It does not share IDs: Oh, Thanks.. > > /* Braswell LPSS devices */ > { "80862288", LPSS_ADDR(byt_pwm_dev_desc) }, > { "8086228A", LPSS_ADDR(byt_uart_dev_desc) }, > { "8086228E", LPSS_ADDR(bsw_spi_dev_desc) }, > { "808622C1", LPSS_ADDR(byt_i2c_dev_desc) }, > > /* The following are Broadwell LPSS IDs _not_ Braswell */ > { "INT3430", LPSS_ADDR(lpt_dev_desc) }, > { "INT3431", LPSS_ADDR(lpt_dev_desc) }, > { "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) }, > { "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) }, > { "INT3434", LPSS_ADDR(lpt_uart_dev_desc) }, > { "INT3435", LPSS_ADDR(lpt_uart_dev_desc) }, > { "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) }, > { "INT3437", }, > > So please make the patch touch only the four 808622* devices above > unless you have tested this on Broadwell as well. > > Otherwise the patch looks good to me. Here is the patch.. >From 970c704dbb05aa8392b6e1090ceaf9ed76b6436b Mon Sep 17 00:00:00 2001 From: Srinidhi Kasagar <srinidhi.kasagar@xxxxxxxxx> Date: Thu, 27 Aug 2015 21:30:55 +0530 Subject: [PATCH] ACPI / LPSS: Ignore 10ms delay for Braswell LPSS devices in Braswell does not need the default 10ms d3_delay imposed by PCI specification. Removing this unnecessary delay significantly reduces the resume time approximately upto 200ms on this platform. Signed-off-by: Srinidhi Kasagar <srinidhi.kasagar@xxxxxxxxx> --- drivers/acpi/acpi_lpss.c | 38 ++++++++++++++++++++++++++++++++------ 1 file changed, 32 insertions(+), 6 deletions(-) diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c index 46b58abb08c5..10020e04f574 100644 --- a/drivers/acpi/acpi_lpss.c +++ b/drivers/acpi/acpi_lpss.c @@ -60,6 +60,7 @@ ACPI_MODULE_NAME("acpi_lpss"); #define LPSS_CLK_DIVIDER BIT(2) #define LPSS_LTR BIT(3) #define LPSS_SAVE_CTX BIT(4) +#define LPSS_NO_D3_DELAY BIT(5) struct lpss_private_data; @@ -156,6 +157,10 @@ static const struct lpss_device_desc byt_pwm_dev_desc = { .flags = LPSS_SAVE_CTX, }; +static const struct lpss_device_desc bsw_pwm_dev_desc = { + .flags = LPSS_SAVE_CTX | LPSS_NO_D3_DELAY, +}; + static const struct lpss_device_desc byt_uart_dev_desc = { .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX, .clk_con_id = "baudclk", @@ -163,6 +168,14 @@ static const struct lpss_device_desc byt_uart_dev_desc = { .setup = lpss_uart_setup, }; +static const struct lpss_device_desc bsw_uart_dev_desc = { + .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX + | LPSS_NO_D3_DELAY, + .clk_con_id = "baudclk", + .prv_offset = 0x800, + .setup = lpss_uart_setup, +}; + static const struct lpss_device_desc byt_spi_dev_desc = { .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX, .prv_offset = 0x400, @@ -178,8 +191,15 @@ static const struct lpss_device_desc byt_i2c_dev_desc = { .setup = byt_i2c_setup, }; +static const struct lpss_device_desc bsw_i2c_dev_desc = { + .flags = LPSS_CLK | LPSS_SAVE_CTX | LPSS_NO_D3_DELAY, + .prv_offset = 0x800, + .setup = byt_i2c_setup, +}; + static struct lpss_device_desc bsw_spi_dev_desc = { - .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX, + .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX + | LPSS_NO_D3_DELAY, .prv_offset = 0x400, .setup = lpss_deassert_reset, }; @@ -214,11 +234,12 @@ static const struct acpi_device_id acpi_lpss_device_ids[] = { { "INT33FC", }, /* Braswell LPSS devices */ - { "80862288", LPSS_ADDR(byt_pwm_dev_desc) }, - { "8086228A", LPSS_ADDR(byt_uart_dev_desc) }, + { "80862288", LPSS_ADDR(bsw_pwm_dev_desc) }, + { "8086228A", LPSS_ADDR(bsw_uart_dev_desc) }, { "8086228E", LPSS_ADDR(bsw_spi_dev_desc) }, - { "808622C1", LPSS_ADDR(byt_i2c_dev_desc) }, + { "808622C1", LPSS_ADDR(bsw_i2c_dev_desc) }, + /* Broadwell LPSS devices */ { "INT3430", LPSS_ADDR(lpt_dev_desc) }, { "INT3431", LPSS_ADDR(lpt_dev_desc) }, { "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) }, @@ -558,9 +579,14 @@ static void acpi_lpss_restore_ctx(struct device *dev, * The following delay is needed or the subsequent write operations may * fail. The LPSS devices are actually PCI devices and the PCI spec * expects 10ms delay before the device can be accessed after D3 to D0 - * transition. + * transition. However some platforms like BSW does not need this delay. */ - msleep(10); + unsigned int delay = 10; /* default 10ms delay */ + + if (pdata->dev_desc->flags & LPSS_NO_D3_DELAY) + delay = 0; + + msleep(delay); for (i = 0; i < LPSS_PRV_REG_COUNT; i++) { unsigned long offset = i * sizeof(u32); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html