diff mbox series

[v2,07/17] PCI: Clean up and document PM/reset delays

Message ID 20200302184429.12880-8-stanspas@amazon.com (mailing list archive)
State Superseded, archived
Headers show
Series Improve PCI device post-reset readiness polling | expand

Commit Message

Stanislav Spassov March 2, 2020, 6:44 p.m. UTC 
From: Stanislav Spassov <stanspas@amazon.de>

...and replace several "magic numbers" scattered throughout the code.

Signed-off-by: Stanislav Spassov <stanspas@amazon.de>
---
 drivers/pci/iov.c      |  4 +--
 drivers/pci/pci-acpi.c |  4 +--
 drivers/pci/pci.c      | 21 +++---------
 drivers/pci/pci.h      | 72 ++++++++++++++++++++++++++++++++++++++++--
 4 files changed, 78 insertions(+), 23 deletions(-)

Comments

kernel test robot March 3, 2020, 1:51 a.m. UTC | #1 
Hi Stanislav,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on bb6d3fb354c5ee8d6bde2d576eb7220ea09862b9]

url:    https://github.com/0day-ci/linux/commits/Stanislav-Spassov/Improve-PCI-device-post-reset-readiness-polling/20200303-043307
base:    bb6d3fb354c5ee8d6bde2d576eb7220ea09862b9
config: arm-multi_v5_defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (GCC) 7.5.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.5.0 make.cross ARCH=arm 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   drivers/pci/controller/pci-mvebu.c: In function 'mvebu_pcie_powerup':
>> drivers/pci/controller/pci-mvebu.c:930:22: error: 'PCI_PM_D3COLD_WAIT' undeclared (first use in this function); did you mean 'PCI_PM_D3HOT_DELAY'?
      u32 reset_udelay = PCI_PM_D3COLD_WAIT * 1000;
                         ^~~~~~~~~~~~~~~~~~
                         PCI_PM_D3HOT_DELAY
   drivers/pci/controller/pci-mvebu.c:930:22: note: each undeclared identifier is reported only once for each function it appears in

vim +930 drivers/pci/controller/pci-mvebu.c

49cb1f718360f8 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  915  
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  916  /*
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  917   * Power up a PCIe port.  PCIe requires the refclk to be stable for 100µs
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  918   * prior to releasing PERST.  See table 2-4 in section 2.6.2 AC Specifications
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  919   * of the PCI Express Card Electromechanical Specification, 1.1.
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  920   */
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  921  static int mvebu_pcie_powerup(struct mvebu_pcie_port *port)
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  922  {
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  923  	int ret;
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  924  
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  925  	ret = clk_prepare_enable(port->clk);
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  926  	if (ret < 0)
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  927  		return ret;
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  928  
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  929  	if (port->reset_gpio) {
8ed81ec82a8c57 drivers/pci/host/pci-mvebu.c Lucas Stach  2017-02-02 @930  		u32 reset_udelay = PCI_PM_D3COLD_WAIT * 1000;
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  931  
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  932  		of_property_read_u32(port->dn, "reset-delay-us",
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  933  				     &reset_udelay);
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  934  
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  935  		udelay(100);
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  936  
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  937  		gpiod_set_value_cansleep(port->reset_gpio, 0);
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  938  		msleep(reset_udelay / 1000);
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  939  	}
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  940  
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  941  	return 0;
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  942  }
d609a8d8e88a42 drivers/pci/host/pci-mvebu.c Russell King 2015-10-03  943  

:::::: The code at line 930 was first introduced by commit
:::::: 8ed81ec82a8c57c3a6ad69b4c4d3e4801163c256 PCI: mvebu: Change delay after reset to the PCIe spec mandated 100ms

:::::: TO: Lucas Stach <l.stach@pengutronix.de>
:::::: CC: Bjorn Helgaas <bhelgaas@google.com>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
kernel test robot March 3, 2020, 2:54 a.m. UTC | #2 
Hi Stanislav,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on bb6d3fb354c5ee8d6bde2d576eb7220ea09862b9]

url:    https://github.com/0day-ci/linux/commits/Stanislav-Spassov/Improve-PCI-device-post-reset-readiness-polling/20200303-043307
base:    bb6d3fb354c5ee8d6bde2d576eb7220ea09862b9
config: arm64-defconfig (attached as .config)
compiler: aarch64-linux-gcc (GCC) 7.5.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.5.0 make.cross ARCH=arm64 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   drivers/pci/controller/pci-aardvark.c: In function 'advk_pcie_setup_hw':
>> drivers/pci/controller/pci-aardvark.c:347:9: error: 'PCI_PM_D3COLD_WAIT' undeclared (first use in this function); did you mean 'PCI_PM_D3HOT_DELAY'?
     msleep(PCI_PM_D3COLD_WAIT);
            ^~~~~~~~~~~~~~~~~~
            PCI_PM_D3HOT_DELAY
   drivers/pci/controller/pci-aardvark.c:347:9: note: each undeclared identifier is reported only once for each function it appears in

vim +347 drivers/pci/controller/pci-aardvark.c

364b3f1ff8f096 drivers/pci/controller/pci-aardvark.c Remi Pommarel    2019-05-22  255  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  256  static void advk_pcie_setup_hw(struct advk_pcie *pcie)
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  257  {
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  258  	u32 reg;
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  259  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  260  	/* Set to Direct mode */
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  261  	reg = advk_readl(pcie, CTRL_CONFIG_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  262  	reg &= ~(CTRL_MODE_MASK << CTRL_MODE_SHIFT);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  263  	reg |= ((PCIE_CORE_MODE_DIRECT & CTRL_MODE_MASK) << CTRL_MODE_SHIFT);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  264  	advk_writel(pcie, reg, CTRL_CONFIG_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  265  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  266  	/* Set PCI global control register to RC mode */
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  267  	reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  268  	reg |= (IS_RC_MSK << IS_RC_SHIFT);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  269  	advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  270  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  271  	/* Set Advanced Error Capabilities and Control PF0 register */
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  272  	reg = PCIE_CORE_ERR_CAPCTL_ECRC_CHK_TX |
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  273  		PCIE_CORE_ERR_CAPCTL_ECRC_CHK_TX_EN |
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  274  		PCIE_CORE_ERR_CAPCTL_ECRC_CHCK |
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  275  		PCIE_CORE_ERR_CAPCTL_ECRC_CHCK_RCV;
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  276  	advk_writel(pcie, reg, PCIE_CORE_ERR_CAPCTL_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  277  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  278  	/* Set PCIe Device Control and Status 1 PF0 register */
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  279  	reg = PCIE_CORE_DEV_CTRL_STATS_RELAX_ORDER_DISABLE |
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  280  		(7 << PCIE_CORE_DEV_CTRL_STATS_MAX_PAYLOAD_SZ_SHIFT) |
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  281  		PCIE_CORE_DEV_CTRL_STATS_SNOOP_DISABLE |
fc31c4e347c9da drivers/pci/host/pci-aardvark.c       Evan Wang        2018-04-06  282  		(PCIE_CORE_DEV_CTRL_STATS_MAX_RD_REQ_SZ <<
fc31c4e347c9da drivers/pci/host/pci-aardvark.c       Evan Wang        2018-04-06  283  		 PCIE_CORE_DEV_CTRL_STATS_MAX_RD_REQ_SIZE_SHIFT);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  284  	advk_writel(pcie, reg, PCIE_CORE_DEV_CTRL_STATS_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  285  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  286  	/* Program PCIe Control 2 to disable strict ordering */
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  287  	reg = PCIE_CORE_CTRL2_RESERVED |
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  288  		PCIE_CORE_CTRL2_TD_ENABLE;
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  289  	advk_writel(pcie, reg, PCIE_CORE_CTRL2_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  290  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  291  	/* Set GEN2 */
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  292  	reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  293  	reg &= ~PCIE_GEN_SEL_MSK;
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  294  	reg |= SPEED_GEN_2;
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  295  	advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  296  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  297  	/* Set lane X1 */
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  298  	reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  299  	reg &= ~LANE_CNT_MSK;
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  300  	reg |= LANE_COUNT_1;
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  301  	advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  302  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  303  	/* Enable link training */
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  304  	reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  305  	reg |= LINK_TRAINING_EN;
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  306  	advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  307  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  308  	/* Enable MSI */
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  309  	reg = advk_readl(pcie, PCIE_CORE_CTRL2_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  310  	reg |= PCIE_CORE_CTRL2_MSI_ENABLE;
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  311  	advk_writel(pcie, reg, PCIE_CORE_CTRL2_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  312  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  313  	/* Clear all interrupts */
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  314  	advk_writel(pcie, PCIE_ISR0_ALL_MASK, PCIE_ISR0_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  315  	advk_writel(pcie, PCIE_ISR1_ALL_MASK, PCIE_ISR1_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  316  	advk_writel(pcie, PCIE_IRQ_ALL_MASK, HOST_CTRL_INT_STATUS_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  317  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  318  	/* Disable All ISR0/1 Sources */
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  319  	reg = PCIE_ISR0_ALL_MASK;
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  320  	reg &= ~PCIE_ISR0_MSI_INT_PENDING;
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  321  	advk_writel(pcie, reg, PCIE_ISR0_MASK_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  322  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  323  	advk_writel(pcie, PCIE_ISR1_ALL_MASK, PCIE_ISR1_MASK_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  324  
f6b6aefee70aa5 drivers/pci/controller/pci-aardvark.c Bjorn Helgaas    2019-05-30  325  	/* Unmask all MSIs */
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  326  	advk_writel(pcie, 0, PCIE_MSI_MASK_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  327  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  328  	/* Enable summary interrupt for GIC SPI source */
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  329  	reg = PCIE_IRQ_ALL_MASK & (~PCIE_IRQ_ENABLE_INTS_MASK);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  330  	advk_writel(pcie, reg, HOST_CTRL_INT_MASK_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  331  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  332  	reg = advk_readl(pcie, PCIE_CORE_CTRL2_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  333  	reg |= PCIE_CORE_CTRL2_OB_WIN_ENABLE;
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  334  	advk_writel(pcie, reg, PCIE_CORE_CTRL2_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  335  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  336  	/* Bypass the address window mapping for PIO */
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  337  	reg = advk_readl(pcie, PIO_CTRL);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  338  	reg |= PIO_CTRL_ADDR_WIN_DISABLE;
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  339  	advk_writel(pcie, reg, PIO_CTRL);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  340  
f4c7d053d7f77c drivers/pci/controller/pci-aardvark.c Remi Pommarel    2019-05-22  341  	/*
f4c7d053d7f77c drivers/pci/controller/pci-aardvark.c Remi Pommarel    2019-05-22  342  	 * PERST# signal could have been asserted by pinctrl subsystem before
f4c7d053d7f77c drivers/pci/controller/pci-aardvark.c Remi Pommarel    2019-05-22  343  	 * probe() callback has been called, making the endpoint going into
f4c7d053d7f77c drivers/pci/controller/pci-aardvark.c Remi Pommarel    2019-05-22  344  	 * fundamental reset. As required by PCI Express spec a delay for at
f4c7d053d7f77c drivers/pci/controller/pci-aardvark.c Remi Pommarel    2019-05-22  345  	 * least 100ms after such a reset before link training is needed.
f4c7d053d7f77c drivers/pci/controller/pci-aardvark.c Remi Pommarel    2019-05-22  346  	 */
f4c7d053d7f77c drivers/pci/controller/pci-aardvark.c Remi Pommarel    2019-05-22 @347  	msleep(PCI_PM_D3COLD_WAIT);
f4c7d053d7f77c drivers/pci/controller/pci-aardvark.c Remi Pommarel    2019-05-22  348  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  349  	/* Start link training */
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  350  	reg = advk_readl(pcie, PCIE_CORE_LINK_CTRL_STAT_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  351  	reg |= PCIE_CORE_LINK_TRAINING;
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  352  	advk_writel(pcie, reg, PCIE_CORE_LINK_CTRL_STAT_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  353  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  354  	advk_pcie_wait_for_link(pcie);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  355  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  356  	reg = PCIE_CORE_LINK_L0S_ENTRY |
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  357  		(1 << PCIE_CORE_LINK_WIDTH_SHIFT);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  358  	advk_writel(pcie, reg, PCIE_CORE_LINK_CTRL_STAT_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  359  
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  360  	reg = advk_readl(pcie, PCIE_CORE_CMD_STATUS_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  361  	reg |= PCIE_CORE_CMD_MEM_ACCESS_EN |
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  362  		PCIE_CORE_CMD_IO_ACCESS_EN |
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  363  		PCIE_CORE_CMD_MEM_IO_REQ_EN;
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  364  	advk_writel(pcie, reg, PCIE_CORE_CMD_STATUS_REG);
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  365  }
8c39d710363c14 drivers/pci/host/pci-aardvark.c       Thomas Petazzoni 2016-06-30  366  

:::::: The code at line 347 was first introduced by commit
:::::: f4c7d053d7f77cd5c1a1ba7c7ce085ddba13d1d7 PCI: aardvark: Wait for endpoint to be ready before training link

:::::: TO: Remi Pommarel <repk@triplefau.lt>
:::::: CC: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff mbox series

Patch

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 4d1f392b05f9..d4e4a0c0a97f 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -524,7 +524,7 @@  static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 	iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
 	pci_cfg_access_lock(dev);
 	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
-	msleep(100);
+	msleep(PCI_VF_ENABLE_DELAY);
 	pci_cfg_access_unlock(dev);
 
 	rc = sriov_add_vfs(dev, initial);
@@ -735,7 +735,7 @@  static void sriov_restore_state(struct pci_dev *dev)
 	pci_iov_set_numvfs(dev, iov->num_VFs);
 	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 	if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
-		msleep(100);
+		msleep(PCI_VF_ENABLE_DELAY);
 }
 
 /**
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 508924377bff..66e8f8199ce0 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -1242,7 +1242,7 @@  static void pci_acpi_optimize_delay(struct pci_dev *pdev,
 			value = (int)(value_us / 1000);
 			if (value_us % 1000 > 0)
 				value++;
-			if (value < PCI_PM_D3COLD_WAIT)
+			if (value < PCI_RESET_DELAY)
 				pdev->d3cold_delay = value;
 		}
 		if (elements[3].type == ACPI_TYPE_INTEGER) {
@@ -1250,7 +1250,7 @@  static void pci_acpi_optimize_delay(struct pci_dev *pdev,
 			value = (int)(value_us / 1000);
 			if (value_us % 1000 > 0)
 				value++;
-			if (value < PCI_PM_D3_WAIT)
+			if (value < PCI_PM_D3HOT_DELAY)
 				pdev->d3_delay = value;
 		}
 	}
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 4899b12b5a38..aaef00578487 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2844,8 +2844,8 @@  void pci_pm_init(struct pci_dev *dev)
 
 	dev->pm_cap = pm;
 	dev->ignore_reset_delay_on_sx_resume = 0;
-	dev->d3_delay = PCI_PM_D3_WAIT;
-	dev->d3cold_delay = PCI_PM_D3COLD_WAIT;
+	dev->d3_delay = PCI_PM_D3HOT_DELAY;
+	dev->d3cold_delay = PCI_RESET_DELAY;
 	dev->bridge_d3 = pci_bridge_d3_possible(dev);
 	dev->d3cold_allowed = true;
 
@@ -4500,12 +4500,7 @@  int pcie_flr(struct pci_dev *dev)
 	if (dev->imm_ready)
 		return 0;
 
-	/*
-	 * Per PCIe r4.0, sec 6.6.2, a device must complete an FLR within
-	 * 100ms, but may silently discard requests while the FLR is in
-	 * progress.  Wait 100ms before trying to access the device.
-	 */
-	msleep(100);
+	msleep(PCI_FLR_DELAY);
 
 	return pci_dev_wait(dev, "FLR", PCIE_RESET_READY_POLL_MS);
 }
@@ -4544,13 +4539,7 @@  static int pci_af_flr(struct pci_dev *dev, int probe)
 	if (dev->imm_ready)
 		return 0;
 
-	/*
-	 * Per Advanced Capabilities for Conventional PCI ECN, 13 April 2006,
-	 * updated 27 July 2006; a device must complete an FLR within
-	 * 100ms, but may silently discard requests while the FLR is in
-	 * progress.  Wait 100ms before trying to access the device.
-	 */
-	msleep(100);
+	msleep(PCI_FLR_DELAY);
 
 	return pci_dev_wait(dev, "AF_FLR", PCIE_RESET_READY_POLL_MS);
 }
@@ -4590,7 +4579,7 @@  static int pci_pm_reset(struct pci_dev *dev, int probe)
 	csr &= ~PCI_PM_CTRL_STATE_MASK;
 	csr |= PCI_D3hot;
 	pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
-	msleep(PCI_PM_D3_WAIT);
+	msleep(PCI_PM_D3HOT_DELAY);
 
 	csr &= ~PCI_PM_CTRL_STATE_MASK;
 	csr |= PCI_D0;
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index c4c3ba926f45..9b5dd6ea2f52 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -43,9 +43,75 @@  int pci_probe_reset_function(struct pci_dev *dev);
 int pci_bridge_secondary_bus_reset(struct pci_dev *dev);
 int pci_bus_error_reset(struct pci_dev *dev);
 
-#define PCI_PM_D2_DELAY         200
-#define PCI_PM_D3_WAIT          10
-#define PCI_PM_D3COLD_WAIT      100
+/*
+ * These constants represent the minimum amounts of time mandated by the
+ * PCI Express Base specification that software needs to wait after
+ * various PCI device events involving (re-)initialization. Only after
+ * the appropriate delay has elapsed, is software permitted to issue
+ * Configuration Requests targeting the affected device.
+ *
+ * Relevant sections in PCI Express Base Specification r5.0 (May 22, 2019):
+ * - 6.6.1 "Conventional Reset" for PCI_RESET_DELAY and PCI_DL_UP_DELAY
+ * - 6.6.2 "Function Level Reset" for PCI_FLR_DELAY
+ * - 5.9 "State Transition Recovery Time Requirements" for PCI_PM_D3HOT_DELAY
+ *        and PCI_PM_D2_DELAY
+ * - 9.3.3.3.1 "VF Enable" for PCI_VF_ENABLE_DELAY
+ *
+ * There are mechanisms to reduce some of the delay values for specific devices:
+ * - a device may expose the Readiness Time Reporting Extended Capability from:
+ *   PCI Express Base Specification r4.0 (September 27, 2017), sec 7.9.17
+ *   (This is currently not supported by the kernel.)
+ * - system firmware may provide overrides using an ACPI _DSM Function 9:
+ *   PCI Firmware Specification r3.2 (January 26, 2015), sec 4.6.9
+ *   (see pci_acpi_optimize_delay)
+ *
+ * Unless overridden by _DSM Function 9, other mechanisms may be used to reduce
+ * or completely avoid some of the delays:
+ * - Readiness Notifications (DRS and FRS)
+ * - the Immediate Readiness bit of the Status Register in the PCI header
+ * - the Immediate_Readiness_on_Return_to_D0 in the Power Management
+ *   Capabilities Register in the PCI Power Management Capability
+ * (None of these are currently supported by the kernel.)
+ *
+ * Note: While devices are required to be responsive to Configuration
+ * Requests after these delays, they may not respond with Successful
+ * Completion status until they complete potentially lengthy internal
+ * initialization sequences. Instead, devices respond with Configuration
+ * Request Retry Status (CRS) Completions. Therefore, additional waiting
+ * is necessary as handled by pci_dev_wait().
+ */
+/*
+ * Conventional (non-FLR) reset delay, including D3cold->D0 transitions,
+ * Secondary Bus Reset, and any platform-specific means of triggering
+ * a Conventional Reset.
+ *
+ * According to PCI Firmware spec r3.2, sec 4.6.9, for devices beneath
+ * downstream ports supporting the Data Link Layer Active Reporting
+ * capability, this delay should not be used (see PCI_DL_UP_DELAY).
+ */
+#define PCI_RESET_DELAY		100
+/*
+ * Post-DL_Up (Data Link Layer Active) delay applicable for devices immediately
+ * under a Downstream Port that is capable of reporting Data Link Layer Ready.
+ * Not to be confused with how much time it takes for the link itself to become
+ * active (see pcie_wait_for_link_delay).
+ */
+#define PCI_DL_UP_DELAY		100
+/*
+ * Post-FLR delay
+ * Also applies to legacy devices supporting AF_FLR per Advanced Capabilities
+ * for Conventional PCI ECN, 13 April 2006, updated 27 July 2006)
+ */
+#define PCI_FLR_DELAY		100
+/*
+ * D0/D1/D2->D3hot and D3hot->D0 delay
+ * The specifications do *not* mention overridability of the ->D3hot direction
+ */
+#define PCI_PM_D3HOT_DELAY	10
+/* Post-VF_Enable delay */
+#define PCI_VF_ENABLE_DELAY	100
+/* D0/D1->D2 and D2->D0 delay */
+#define PCI_PM_D2_DELAY		200
 
 /**
  * struct pci_platform_pm_ops - Firmware PM callbacks