From: Tejun Heo Date: Tue, 22 Aug 2006 16:00:27 +0000 (+0900) Subject: [PATCH] sata_via: use old SCR access pattern on vt6420 X-Git-Tag: v2.6.18-rc5~60^2 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ac2164d5e425fa4755bdbab9641d8dab7239b6f5;p=linux-2.6 [PATCH] sata_via: use old SCR access pattern on vt6420 vt6420 has super-fragile SCR registers which can hang the whole machine if accessed with the wrong timings. This patch makes sata_via use SCR registers only during probing and with the same timings as before (pre new EH), which is proven to work. Signed-off-by: Tejun Heo Signed-off-by: Jeff Garzik --- diff --git a/drivers/scsi/sata_via.c b/drivers/scsi/sata_via.c index 03baec2191..01d40369a8 100644 --- a/drivers/scsi/sata_via.c +++ b/drivers/scsi/sata_via.c @@ -74,6 +74,7 @@ enum { static int svia_init_one (struct pci_dev *pdev, const struct pci_device_id *ent); static u32 svia_scr_read (struct ata_port *ap, unsigned int sc_reg); static void svia_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val); +static void vt6420_error_handler(struct ata_port *ap); static const struct pci_device_id svia_pci_tbl[] = { { 0x1106, 0x3149, PCI_ANY_ID, PCI_ANY_ID, 0, 0, vt6420 }, @@ -107,7 +108,38 @@ static struct scsi_host_template svia_sht = { .bios_param = ata_std_bios_param, }; -static const struct ata_port_operations svia_sata_ops = { +static const struct ata_port_operations vt6420_sata_ops = { + .port_disable = ata_port_disable, + + .tf_load = ata_tf_load, + .tf_read = ata_tf_read, + .check_status = ata_check_status, + .exec_command = ata_exec_command, + .dev_select = ata_std_dev_select, + + .bmdma_setup = ata_bmdma_setup, + .bmdma_start = ata_bmdma_start, + .bmdma_stop = ata_bmdma_stop, + .bmdma_status = ata_bmdma_status, + + .qc_prep = ata_qc_prep, + .qc_issue = ata_qc_issue_prot, + .data_xfer = ata_pio_data_xfer, + + .freeze = ata_bmdma_freeze, + .thaw = ata_bmdma_thaw, + .error_handler = vt6420_error_handler, + .post_internal_cmd = ata_bmdma_post_internal_cmd, + + .irq_handler = ata_interrupt, + .irq_clear = ata_bmdma_irq_clear, + + .port_start = ata_port_start, + .port_stop = ata_port_stop, + .host_stop = ata_host_stop, +}; + +static const struct ata_port_operations vt6421_sata_ops = { .port_disable = ata_port_disable, .tf_load = ata_tf_load, @@ -141,13 +173,13 @@ static const struct ata_port_operations svia_sata_ops = { .host_stop = ata_host_stop, }; -static struct ata_port_info svia_port_info = { +static struct ata_port_info vt6420_port_info = { .sht = &svia_sht, .host_flags = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY, .pio_mask = 0x1f, .mwdma_mask = 0x07, .udma_mask = 0x7f, - .port_ops = &svia_sata_ops, + .port_ops = &vt6420_sata_ops, }; MODULE_AUTHOR("Jeff Garzik"); @@ -170,6 +202,81 @@ static void svia_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val) outl(val, ap->ioaddr.scr_addr + (4 * sc_reg)); } +/** + * vt6420_prereset - prereset for vt6420 + * @ap: target ATA port + * + * SCR registers on vt6420 are pieces of shit and may hang the + * whole machine completely if accessed with the wrong timing. + * To avoid such catastrophe, vt6420 doesn't provide generic SCR + * access operations, but uses SStatus and SControl only during + * boot probing in controlled way. + * + * As the old (pre EH update) probing code is proven to work, we + * strictly follow the access pattern. + * + * LOCKING: + * Kernel thread context (may sleep) + * + * RETURNS: + * 0 on success, -errno otherwise. + */ +static int vt6420_prereset(struct ata_port *ap) +{ + struct ata_eh_context *ehc = &ap->eh_context; + unsigned long timeout = jiffies + (HZ * 5); + u32 sstatus, scontrol; + int online; + + /* don't do any SCR stuff if we're not loading */ + if (!ATA_PFLAG_LOADING) + goto skip_scr; + + /* Resume phy. This is the old resume sequence from + * __sata_phy_reset(). + */ + svia_scr_write(ap, SCR_CONTROL, 0x300); + svia_scr_read(ap, SCR_CONTROL); /* flush */ + + /* wait for phy to become ready, if necessary */ + do { + msleep(200); + if ((svia_scr_read(ap, SCR_STATUS) & 0xf) != 1) + break; + } while (time_before(jiffies, timeout)); + + /* open code sata_print_link_status() */ + sstatus = svia_scr_read(ap, SCR_STATUS); + scontrol = svia_scr_read(ap, SCR_CONTROL); + + online = (sstatus & 0xf) == 0x3; + + ata_port_printk(ap, KERN_INFO, + "SATA link %s 1.5 Gbps (SStatus %X SControl %X)\n", + online ? "up" : "down", sstatus, scontrol); + + /* SStatus is read one more time */ + svia_scr_read(ap, SCR_STATUS); + + if (!online) { + /* tell EH to bail */ + ehc->i.action &= ~ATA_EH_RESET_MASK; + return 0; + } + + skip_scr: + /* wait for !BSY */ + ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT); + + return 0; +} + +static void vt6420_error_handler(struct ata_port *ap) +{ + return ata_bmdma_drive_eh(ap, vt6420_prereset, ata_std_softreset, + NULL, ata_std_postreset); +} + static const unsigned int svia_bar_sizes[] = { 8, 4, 8, 4, 16, 256 }; @@ -210,7 +317,7 @@ static void vt6421_init_addrs(struct ata_probe_ent *probe_ent, static struct ata_probe_ent *vt6420_init_probe_ent(struct pci_dev *pdev) { struct ata_probe_ent *probe_ent; - struct ata_port_info *ppi = &svia_port_info; + struct ata_port_info *ppi = &vt6420_port_info; probe_ent = ata_pci_init_native_mode(pdev, &ppi, ATA_PORT_PRIMARY | ATA_PORT_SECONDARY); if (!probe_ent) @@ -239,7 +346,7 @@ static struct ata_probe_ent *vt6421_init_probe_ent(struct pci_dev *pdev) probe_ent->sht = &svia_sht; probe_ent->host_flags = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY; - probe_ent->port_ops = &svia_sata_ops; + probe_ent->port_ops = &vt6421_sata_ops; probe_ent->n_ports = N_PORTS; probe_ent->irq = pdev->irq; probe_ent->irq_flags = IRQF_SHARED;