Hi Pali, On Thu, Jun 09 2022, Pali Rohár wrote: > On Monday 07 February 2022 16:51:25 Baruch Siach wrote: >> From: Baruch Siach <baruch.siach@xxxxxxxxx> >> >> The PCIE_CAP_LINK1_VAL macro actually defines slot capabilities. Use >> PCI_EXP_SLTCAP_* macros to spell its value, and rename it to better >> describe its meaning. >> >> Signed-off-by: Baruch Siach <baruch.siach@xxxxxxxxx> >> --- >> drivers/pci/controller/dwc/pcie-qcom.c | 15 +++++++++++++-- >> 1 file changed, 13 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c >> index c19cd506ed3f..01e58b057d2a 100644 >> --- a/drivers/pci/controller/dwc/pcie-qcom.c >> +++ b/drivers/pci/controller/dwc/pcie-qcom.c >> @@ -69,7 +69,18 @@ >> #define PCIE20_AXI_MSTR_RESP_COMP_CTRL1 0x81c >> #define CFG_BRIDGE_SB_INIT BIT(0) >> >> -#define PCIE_CAP_LINK1_VAL 0x2FD7F >> +#define PCIE_CAP_SLOT_POWER_LIMIT_VAL 0x7D00 >> +#define PCIE_CAP_SLOT_POWER_LIMIT_SCALE 0x8000 > > Hello! > > Please do not use hardcoded values for slot power limit value and scale > numbers. There are macros PCI_EXP_SLTCAP_SPLV and PCI_EXP_SLTCAP_SPLS > for composing mask: > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/uapi/linux/pci_regs.h?h=v5.19-rc1#n593 > Which could be used together with FIELD_PREP(). See e.g. aardvark commit: > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0d5b8c298545c827ca9f2461b2655277ce0aef79 Thanks for the tip. > And the important information: Slot power limit is board specific and > depends on how power supply and power regulators are designed. So slot > power limit **cannot** be hardcoded in driver. Instead this value should > be read from device tree file for the current board. > > There is a new kernel function of_pci_get_slot_power_limit() which reads > it and compose PCIe slot power limit value and scale numbers. See: > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pci/of.c?h=v5.19-rc1#n631 The 'slot-power-limit-milliwatt' property appears to be undocumented as of v5.19-rc1. This patch should make no functional change. I guess we should keep the default hard-coded driver value for compatibility with existing DTs with no 'slot-power-limit-milliwatt'. Thanks, baruch >> +#define PCIE_CAP_SLOT_VAL (PCI_EXP_SLTCAP_ABP | \ >> + PCI_EXP_SLTCAP_PCP | \ >> + PCI_EXP_SLTCAP_MRLSP | \ >> + PCI_EXP_SLTCAP_AIP | \ >> + PCI_EXP_SLTCAP_PIP | \ >> + PCI_EXP_SLTCAP_HPS | \ >> + PCI_EXP_SLTCAP_HPC | \ >> + PCI_EXP_SLTCAP_EIP | \ >> + PCIE_CAP_SLOT_POWER_LIMIT_VAL | \ >> + PCIE_CAP_SLOT_POWER_LIMIT_SCALE) >> >> #define PCIE20_PARF_Q2A_FLUSH 0x1AC >> >> @@ -1111,7 +1122,7 @@ static int qcom_pcie_init_2_3_3(struct qcom_pcie *pcie) >> >> writel(PCI_COMMAND_MASTER, pci->dbi_base + PCI_COMMAND); >> writel(DBI_RO_WR_EN, pci->dbi_base + PCIE20_MISC_CONTROL_1_REG); >> - writel(PCIE_CAP_LINK1_VAL, pci->dbi_base + offset + PCI_EXP_SLTCAP); >> + writel(PCIE_CAP_SLOT_VAL, pci->dbi_base + offset + PCI_EXP_SLTCAP); >> >> val = readl(pci->dbi_base + offset + PCI_EXP_LNKCAP); >> val &= ~PCI_EXP_LNKCAP_ASPMS; >> -- >> 2.34.1 >> -- ~. .~ Tk Open Systems =}------------------------------------------------ooO--U--Ooo------------{= - baruch@xxxxxxxxxx - tel: +972.52.368.4656, http://www.tkos.co.il -
