On Fri, Nov 5, 2021 at 3:04 PM Pali Rohár pali@kernel.org wrote:
On Friday 05 November 2021 22:09:47 Pali Rohár wrote:
On Friday 05 November 2021 12:54:24 Roman Bacik wrote:
pci_read_word16(bp->pdev,PCI_SUBSYSTEM_VENDOR_ID,&bp->subsystem_vendor);pci_read_word16(bp->pdev, PCI_SUBSYSTEM_ID, &bp-subsystem_device);
pci_read_word16(bp->pdev, PCI_COMMAND, &bp->cmd_reg);pci_read_byte(bp->pdev, PCICFG_ME_REGISTER, &bp->pf_num);PCICFG_ME_REGISTER looks like an error as there is no such PCI config space macro. What you are trying to read into pf_num? Currently I do not know what "pf" abbreviation could mean.
PF stands for physical function and pf_num is the number of physical functions configured. The macro is defined in bnxt.h: #define PCICFG_ME_REGISTER 0x98
pci_read_byte() reads from PCI(e) config space, which is standardized. Therefore only standard macro constants from include/pci.h should be used. Standard PCI config header is 64 byte long and after that is linked list of capabilities. Order of capabilities is not defined. Extended capabilities from linked list should be located by macro constants PCI_CAP_ID_*.
So above register is part of some extended capability. Correctly it should be used some function to locate starting offset of that extended capability based on PCI_CAP_ID_* (see pci.h file for these functions) and then access that register as offset + PCI_* constant (which defined as relative to the start of extended capability). In case standard macro for this constant in pci.h is missing, it is a good idea to define it, or copy it from linux header file pci_regs.h (to have consistent naming of macros).
Just one example how to read PCIe Link Control Register (to make it clear what I mean):
int ret; u16 lnkctl; int pci_exp_off; pci_exp_off = dm_pci_find_capability(dev, PCI_CAP_ID_EXP); if (!pci_exp_off) return -ENOENT; ret = dm_pci_read_config16(dev, pci_exp_off + PCI_EXP_LNKCTL, &lnkctl); if (ret) return ret;
The driver should work for 0x14e4:0x16F0 and we usually test it with this one. We will use your recommended method if needed. We will try to remove it in v8, since I do not see bp->pf_num being used.
Thank you very much,
Roman