Hello.
Fajun Chen wrote:
Could someone help me interpret the code snippet below:
static int sil680_bus_reset(struct ata_port *ap,unsigned int *classes)
{
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
unsigned long addr = sil680_selreg(ap, 0);
u8 reset;
pci_read_config_byte(pdev, addr, &reset);
pci_write_config_byte(pdev, addr, reset | 0x03); // ?
udelay(25);
pci_write_config_byte(pdev, addr, reset);
return ata_std_softreset(ap, classes);
}
Based on Sil680 data sheet, channel reset bit is bit 2, why the reset
code above is not "pci_write_config_byte(pdev, addr, reset | 0x04);"?
I guess it's been blindly copied over form drivers/ide/pci/siimage.c...
The code indeed does seem meaningless. For the libata it could make sense to
set bit 2 for the hardreset -- but then sil680_error_handler() needs to be
turn into ata_bmdma_drive_eh(ap, ata_std_prereset, ata_std_softreset,
sil680_bus_reset, ata_std_postreset)...
For the legacy driver, this function needs to be converted to something
sane too...
Thanks in advance!
MBR, Sergei
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