This patch adds support for SATA over SAS expanders to the previous two SATA support in libsas patches. There were a couple of nasty non trivial things to sort out before this one could be made to work. Firstly, I'd like to thank Doug Gilbert for diagnosing a problem with the LSI expanders where the REPORT_SATA_PHY command was returning the D2H FIS in the wrong order (Although, here, I think I have to blame the SAS standards which specifies the FIS "shall be returned in little endian format" and later on "which means resp[24] shall be FIS type" The latter, of course, implying big endian format). Just to make sure, I put a check for the D2H FIS type being in the wrong position and reverse the FIS data if it is. The second is a problem outlined in Annex G of the SAS standard (again, a technical point with D2H FIS ... necessitating a phy reset on certain conditions). With the patch, I can now see my SATA-1 disk in a cascaded expander configuration. James --- Index: BUILD-2.6/drivers/scsi/libsas/sas_expander.c =================================================================== --- BUILD-2.6.orig/drivers/scsi/libsas/sas_expander.c 2006-08-21 21:49:14.000000000 -0500 +++ BUILD-2.6/drivers/scsi/libsas/sas_expander.c 2006-08-22 09:10:40.000000000 -0500 @@ -36,6 +36,8 @@ static int sas_configure_phy(struct domain_device *dev, int phy_id, u8 *sas_addr, int include); static int sas_disable_routing(struct domain_device *dev, u8 *sas_addr); +static int smp_phy_control(struct domain_device *dev, int phy_id, + enum phy_func phy_func); #if 0 /* FIXME: smp needs to migrate into the sas class */ @@ -221,6 +223,36 @@ #define DISCOVER_REQ_SIZE 16 #define DISCOVER_RESP_SIZE 56 +static int sas_ex_phy_discover_helper(struct domain_device *dev, u8 *disc_req, + u8 *disc_resp, int single) +{ + int i, res; + + disc_req[9] = single; + for (i = 1 ; i < 3; i++) { + struct discover_resp *dr; + + res = smp_execute_task(dev, disc_req, DISCOVER_REQ_SIZE, + disc_resp, DISCOVER_RESP_SIZE); + if (res) + return res; + /* This is detecting a failure to transmit inital + * dev to host FIS as described in section G.5 of + * sas-2 r 04b */ + dr = &((struct smp_resp *)disc_resp)->disc; + if (!(dr->attached_dev_type == 0 && + dr->attached_sata_dev)) + break; + /* In order to generate the dev to host FIS, we + * send a link reset to the expander port */ + smp_phy_control(dev, single, PHY_FUNC_LINK_RESET); + /* Wait for the reset to trigger the negotiation */ + msleep(500); + } + sas_set_ex_phy(dev, single, disc_resp); + return 0; +} + static int sas_ex_phy_discover(struct domain_device *dev, int single) { struct expander_device *ex = &dev->ex_dev; @@ -241,23 +273,15 @@ disc_req[1] = SMP_DISCOVER; if (0 <= single && single < ex->num_phys) { - disc_req[9] = single; - res = smp_execute_task(dev, disc_req, DISCOVER_REQ_SIZE, - disc_resp, DISCOVER_RESP_SIZE); - if (res) - goto out_err; - sas_set_ex_phy(dev, single, disc_resp); + res = sas_ex_phy_discover_helper(dev, disc_req, disc_resp, single); } else { int i; for (i = 0; i < ex->num_phys; i++) { - disc_req[9] = i; - res = smp_execute_task(dev, disc_req, - DISCOVER_REQ_SIZE, disc_resp, - DISCOVER_RESP_SIZE); + res = sas_ex_phy_discover_helper(dev, disc_req, + disc_resp, i); if (res) goto out_err; - sas_set_ex_phy(dev, i, disc_resp); } } out_err: @@ -492,6 +516,7 @@ { int res; u8 *rps_req = alloc_smp_req(RPS_REQ_SIZE); + u8 *resp = (u8 *)rps_resp; if (!rps_req) return -ENOMEM; @@ -502,8 +527,28 @@ res = smp_execute_task(dev, rps_req, RPS_REQ_SIZE, rps_resp, RPS_RESP_SIZE); + /* 0x34 is the FIS type for the D2H fis. There's a potential + * standards cockup here. sas-2 explicitly specifies the FIS + * should be encoded so that FIS type is in resp[24]. + * However, some expanders endian reverse this. Undo the + * reversal here */ + if (!res && resp[27] == 0x34 && resp[24] != 0x34) { + int i; + + for (i = 0; i < 5; i++) { + int j = 24 + (i*4); + u8 a, b; + a = resp[j + 0]; + b = resp[j + 1]; + resp[j + 0] = resp[j + 3]; + resp[j + 1] = resp[j + 2]; + resp[j + 2] = b; + resp[j + 3] = a; + } + } + kfree(rps_req); - return 0; + return res; } static void sas_ex_get_linkrate(struct domain_device *parent, @@ -584,7 +629,19 @@ } memcpy(child->frame_rcvd, &child->sata_dev.rps_resp.rps.fis, sizeof(struct dev_to_host_fis)); + + rphy = sas_end_device_alloc(phy->port); + /* FIXME: error handling */ + BUG_ON(!rphy); + sas_init_dev(child); + + child->rphy = rphy; + + spin_lock(&parent->port->dev_list_lock); + list_add_tail(&child->dev_list_node, &parent->port->dev_list); + spin_unlock(&parent->port->dev_list_lock); + res = sas_discover_sata(child); if (res) { SAS_DPRINTK("sas_discover_sata() for device %16llx at " - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html