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Date: Tue, 14 Jun 2016 12:43:55 +0200
From: Ingo Molnar <mingo@...nel.org>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc: Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>,
"H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
Bjorn Helgaas <bhelgaas@...gle.com>, linux-pci@...r.kernel.org,
Mika Westerberg <mika.westerberg@...ux.intel.com>,
linux-kernel@...r.kernel.org,
David Cohen <david.a.cohen@...ux.intel.com>,
Peter Zijlstra <a.p.zijlstra@...llo.nl>
Subject: Re: [PATCH v1 1/1] x86/platform/intel-mid: Add Power Management Unit
driver
* Andy Shevchenko <andriy.shevchenko@...ux.intel.com> wrote:
> Add Power Management Unit driver to handle power states of South Complex
> devices on Intel Tangier. In the future it might be expanded to cover North
> Complex devices as well.
>
> With this driver the power state of the host controllers such as SPI, I2C,
> UART, eMMC, and DMA would be managed.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> ---
> arch/x86/include/asm/intel-mid.h | 8 +
> arch/x86/pci/intel_mid_pci.c | 35 +++-
> arch/x86/platform/intel-mid/Makefile | 2 +-
> arch/x86/platform/intel-mid/pmu.c | 392 +++++++++++++++++++++++++++++++++++
> drivers/pci/Makefile | 3 +
> drivers/pci/pci-mid.c | 77 +++++++
> 6 files changed, 515 insertions(+), 2 deletions(-)
> create mode 100644 arch/x86/platform/intel-mid/pmu.c
> create mode 100644 drivers/pci/pci-mid.c
So this collides with perf's 'PMU' naming massively. Can we pick another name
before hillarious kernel-wide confusion spreads?
how about intel/mid/pm.c plus renaming all the pmu* internal names to pm*?
We could call it 'power management interface', and in a single line mention that
this is also a 'Power Management Unit' in Intel-speak?
> extern int intel_mid_pci_init(void);
> +int intel_mid_pci_set_power_state(struct pci_dev *pdev, pci_power_t state);
> +
> +#define INTEL_MID_PMU_LSS_OFFSET 4
> +#define INTEL_MID_PMU_LSS_TYPE (1 << 7)
> +
> +int intel_mid_pmu_get_lss_id(struct pci_dev *pdev);
Yeah, so please be consistent about 'extern'.
Also, I had a look at the resulting arch/x86/include/asm/intel-mid.h and the
vertical alignments are all over the map.
Here is how it looks like:
#define FSB_FREQ_83SKU 83200
#define FSB_FREQ_100SKU 99840
#define FSB_FREQ_133SKU 133000
#define FSB_FREQ_167SKU 167000
#define FSB_FREQ_200SKU 200000
#define FSB_FREQ_267SKU 267000
#define FSB_FREQ_333SKU 333000
#define FSB_FREQ_400SKU 400000
/* Bus Select SoC Fuse value */
#define BSEL_SOC_FUSE_MASK 0x7
#define BSEL_SOC_FUSE_001 0x1 /* FSB 133MHz */
#define BSEL_SOC_FUSE_101 0x5 /* FSB 100MHz */
#define BSEL_SOC_FUSE_111 0x7 /* FSB 83MHz */
#define SFI_MTMR_MAX_NUM 8
#define SFI_MRTC_MAX 8
Can we please improve that?
> +
> +static void mrst_power_off_unused_dev(struct pci_dev *dev)
> +{
> + mid_power_off_dev(dev);
> +}
> DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0801, mrst_power_off_unused_dev);
So we add mrst_power_off_unused_dev() just to make it to mid_power_off_dev()?
Also, newlines ran out when the above bit was written.
> +++ b/arch/x86/platform/intel-mid/pmu.c
> @@ -0,0 +1,392 @@
> +/*
> + * Intel MID Power Management Unit device driver
Could we please write a bit longer description about what this driver does, what
interfaces/capabilities it enables, etc.? People like the warm fuzzy feeling
associated with knowing what's going on.
> +#include <linux/delay.h>
> +#include <linux/errno.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/pci.h>
> +#include <linux/types.h>
Was that types.h include really needed?
> +/* Registers */
> +#define PM_STS 0x00
> +#define PM_CMD 0x04
> +#define PM_ICS 0x08
> +#define PM_WKC(x) (0x10 + (x) * 4)
> +#define PM_WKS(x) (0x18 + (x) * 4)
> +#define PM_SSC(x) (0x20 + (x) * 4)
> +#define PM_SSS(x) (0x30 + (x) * 4)
> +
> +/* Bits in PM_STS */
> +#define PM_STS_BUSY (1 << 8)
> +
> +/* Bits in PM_CMD */
> +#define PM_CMD_CMD(x) ((x) << 0)
> +#define PM_CMD_IOC (1 << 8)
> +#define PM_CMD_D3cold (1 << 21)
> +
> +/* List of commands */
> +#define CMD_SET_CFG 0x01
> +
> +/* Bits in PM_ICS */
> +#define PM_ICS_INT_STATUS(x) ((x) & 0xff)
> +#define PM_ICS_IE (1 << 8)
> +#define PM_ICS_IP (1 << 9)
> +#define PM_ICS_SW_INT_STS (1 << 10)
> +
> +/* List of interrupts */
> +#define INT_INVALID 0
> +#define INT_CMD_COMPLETE 1
> +#define INT_CMD_ERR 2
> +#define INT_WAKE_EVENT 3
> +#define INT_LSS_POWER_ERR 4
> +#define INT_S0iX_MSG_ERR 5
> +#define INT_NO_C6 6
> +#define INT_TRIGGER_ERR 7
> +#define INT_INACTIVITY 8
> +
> +/* South Complex devices */
> +#define LSS_MAX_SHARED_DEVS 4
> +#define LSS_MAX_DEVS 64
> +
> +#define LSS_WS_BITS 1 /* wake state width */
> +#define LSS_PWS_BITS 2 /* power state width */
> +
> +/* Supported device IDs */
> +#define PCI_DEVICE_ID_TANGIER 0x11a1
Again essentially randomized vertical alignment. Is anyone supposed to read this
code?
> + /* Find device in cache or first free cell */
> + for (j = 0; j < LSS_MAX_SHARED_DEVS; j++)
> + if (lss[j].pdev == pdev || !lss[j].pdev)
> + break;
... missing curly braces. That's a problem in other places as well, please fix all
of them.
> +static int tng_set_initial_state(struct mid_pmu *pmu)
> +{
> + unsigned int i, j;
> + int ret;
> +
> + /* Enable wake events */
> + mid_pmu_set_wake(pmu, 0, 0xffffffff);
> + mid_pmu_set_wake(pmu, 1, 0xffffffff);
> +
> + /* Power off unused devices */
> + mid_pmu_set_state(pmu, 0, 0xffffffff);
> + mid_pmu_set_state(pmu, 1, 0xffffffff);
> + mid_pmu_set_state(pmu, 2, 0xffffffff);
> + mid_pmu_set_state(pmu, 3, 0xffffffff);
What are these magic numbers of 0/1/2/3?
> +static struct pci_driver mid_pmu_pci_driver = {
> + .name = "intel_mid_pmu",
> + .probe = mid_pmu_probe,
> + .id_table = mid_pmu_pci_ids,
> +};
This structure initialization has a nice vertical layout.
> +static struct pci_platform_pm_ops mid_pci_platform_pm = {
> + .is_manageable = mid_pci_power_manageable,
> + .set_state = mid_pci_set_power_state,
> + .choose_state = mid_pci_choose_state,
> + .sleep_wake = mid_pci_sleep_wake,
> + .run_wake = mid_pci_run_wake,
> + .need_resume = mid_pci_need_resume,
> +};
This one, not so much.
Thanks,
Ingo
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