From: Tejun Heo Date: Mon, 19 Nov 2007 07:03:44 +0000 (+0900) Subject: ahci: update PCS programming X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=49f290903935612aadab3899a4aca884c1140348;p=linux-beck.git ahci: update PCS programming For intel ones, ahci unconditionally OR'd 0xf to PCS. This isn't correct for the following cases. * ich6/7m's which only implement P0 and P2 (0xf works fine tho) * ich8/9's which have six ports and needs 0x3f to enable all ports This patch updates PCS programming such that... * port_map determined by ahci_save_initial_config() is OR'd instead of 0xf * PCS is updated only if necessary (there are turned off enable bits) port_map is determined from PORTS_IMPL PCI register which is implemented as write or write-once register. If the register isn't programmed, ahci automatically generates it from number of ports, which is good enough for PCS programming. ICH6/7M are probably the only ones where non-contiguous enable bits are necessary && PORTS_IMPL isn't programmed properly but they're proven to work reliably with 0xf anyway. Signed-off-by: Tejun Heo Signed-off-by: Jeff Garzik --- diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index 54f38c21dd95..ef5e6b6e6e69 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -1036,6 +1036,7 @@ static int ahci_deinit_port(struct ata_port *ap, const char **emsg) static int ahci_reset_controller(struct ata_host *host) { struct pci_dev *pdev = to_pci_dev(host->dev); + struct ahci_host_priv *hpriv = host->private_data; void __iomem *mmio = host->iomap[AHCI_PCI_BAR]; u32 tmp; @@ -1078,8 +1079,10 @@ static int ahci_reset_controller(struct ata_host *host) /* configure PCS */ pci_read_config_word(pdev, 0x92, &tmp16); - tmp16 |= 0xf; - pci_write_config_word(pdev, 0x92, tmp16); + if ((tmp16 & hpriv->port_map) != hpriv->port_map) { + tmp16 |= hpriv->port_map; + pci_write_config_word(pdev, 0x92, tmp16); + } } return 0;