Messages in this thread | | | Date | Wed, 16 Jan 2002 19:52:30 -0600 | From | Gerald Champagne <> | Subject | Re: Promise 20268 PCI register decoding |
| |
I just checked 2.5.3-pre1 and it still makes references to registers above 0x0f. I see many references to registers at 0x11, 0x1b, 0x1f. For example, the following:
unsigned long atapi_reg = high_16 + (hwif->channel ? 0x24 : 0x00);
That assumes atapi_reg will be 0x24 beyond the base of bar4 (high_16). Is my PCI code showing me an incorrect size for bar4, or is this accessing registers beyond its limits?
Thanks.
Gerald
Andre Hedrick wrote:
> I fixed that problem after it was discovered. > It is in the newest drivers. > > > On Wed, 16 Jan 2002, Gerald Champagne wrote: > > >>I thought I understood the way PCI devices are accessed in Linux, >>but the code for the Promise PCI controllers has me confused. To >>me it looks like the code is accessing registers outside the area >>allocated to the PCI device during initialization. >> >>The device is configured with the following resources (on a Mips-based >>platform): >> >>00:08.0 Class 0180: 105a:4d68 (rev 01) >> I/O at 0x00000080 [size=0x8] >> I/O at 0x00000088 [size=0x4] >> I/O at 0x00000090 [size=0x8] >> I/O at 0x00000098 [size=0x4] >> I/O at 0x000000a0 [size=0x10] >> Mem at 0x08004000 [size=0x4000] >> >>The Promise code uses registers specified using bar4 but it uses offsets >>above 0x0f. Here's an example of the code in drivers/ide/pdc202xx.c: >> >>void pdc202xx_reset (ide_drive_t *drive) >>{ >> unsigned long high_16 = pci_resource_start(HWIF(drive)->pci_dev, 4); >> byte udma_speed_flag = inb(high_16 + 0x001f); >> >> OUT_BYTE(udma_speed_flag | 0x10, high_16 + 0x001f); >> mdelay(100); >> OUT_BYTE(udma_speed_flag & ~0x10, high_16 + 0x001f); >> mdelay(2000); /* 2 seconds ?! */ >>} >> >>How can the code above try to write to a register 0x1f into a region with >>a size of 0x10? Wouldn't that stomp on the registers of some other PCI device? >> >>Thanks. >> >>Gerald >> >>- >>To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >>the body of a message to majordomo@vger.kernel.org >>More majordomo info at http://vger.kernel.org/majordomo-info.html >>Please read the FAQ at http://www.tux.org/lkml/ >> >> > > > >
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |