Hello.
Please, help me to investigate why the delays present in the
"mpc5xxx_read_config_dword" and "mpc5xxx_write_config_dword" functions
in the "arch/ppc/kernel/mpc52xx_pci.c" file.
I.e.
==========================
*(volatile u32 *)MPC5xxx_PCI_CAR = 0;
udelay(10);
return 0;
==========================
I was neither able to find any reference at the MPC5200 documentation
supplied by FreeScale nor reproduce any error with these lines got
removed.
Thank you.
--
Roman Kuzmenko [off-list ref]
Auriga, Inc.
Roman Kuzmenko wrote:
Hello.
Please, help me to investigate why the delays present in the
"mpc5xxx_read_config_dword" and "mpc5xxx_write_config_dword" functions
in the "arch/ppc/kernel/mpc52xx_pci.c" file.
I.e.
==========================
*(volatile u32 *)MPC5xxx_PCI_CAR = 0;
quoted
udelay(10);
return 0;
==========================
I was neither able to find any reference at the MPC5200 documentation
supplied by FreeScale nor reproduce any error with these lines got
removed.
Thank you.
kernel version?
--
Regards
Andrey Volkov
Roman Kuzmenko wrote:
Hello.
Please, help me to investigate why the delays present in the
"mpc5xxx_read_config_dword" and "mpc5xxx_write_config_dword" functions
in the "arch/ppc/kernel/mpc52xx_pci.c" file.
I.e.
==========================
*(volatile u32 *)MPC5xxx_PCI_CAR = 0;
quoted
udelay(10);
return 0;
==========================
I was neither able to find any reference at the MPC5200 documentation
supplied by FreeScale nor reproduce any error with these lines got
removed.
I wasn't able to reproduce any problem either but people kept reporting
problems. But it seems that it's not a delay that's needed but a mb() to
ensure the write all _completly_ done before the next write. A
udelay(10) almost ensure that also but is a lot less elegant imho.
Sylvain