From: Ondrej Zary linux@zary.sk
[ Upstream commit f343e578fef99a69b3322aca38b94a6d8ded2ce7 ]
Some parallel adapters (e.g. EXP Computer MC-1285B EPP Cable) return bogus values when there's no master device present. This can cause reset to fail, preventing the lone slave device (such as EXP Computer CD-865) from working.
Add custom version of wait_after_reset that ignores master failure when a slave device is present. The custom version is also needed because the generic ata_sff_wait_after_reset uses direct port I/O for slave device detection.
Signed-off-by: Ondrej Zary linux@zary.sk Reviewed-by: Sergey Shtylyov s.shtylyov@omp.ru Signed-off-by: Damien Le Moal dlemoal@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/ata/pata_parport/pata_parport.c | 68 ++++++++++++++++++++++++- 1 file changed, 67 insertions(+), 1 deletion(-)
diff --git a/drivers/ata/pata_parport/pata_parport.c b/drivers/ata/pata_parport/pata_parport.c index 1af64d435d3c2..cd5463970be2e 100644 --- a/drivers/ata/pata_parport/pata_parport.c +++ b/drivers/ata/pata_parport/pata_parport.c @@ -73,6 +73,72 @@ static bool pata_parport_devchk(struct ata_port *ap, unsigned int device) return (nsect == 0x55) && (lbal == 0xaa); }
+static int pata_parport_wait_after_reset(struct ata_link *link, + unsigned int devmask, + unsigned long deadline) +{ + struct ata_port *ap = link->ap; + struct pi_adapter *pi = ap->host->private_data; + unsigned int dev0 = devmask & (1 << 0); + unsigned int dev1 = devmask & (1 << 1); + int rc, ret = 0; + + ata_msleep(ap, ATA_WAIT_AFTER_RESET); + + /* always check readiness of the master device */ + rc = ata_sff_wait_ready(link, deadline); + if (rc) { + /* + * some adapters return bogus values if master device is not + * present, so don't abort now if a slave device is present + */ + if (!dev1) + return rc; + ret = -ENODEV; + } + + /* + * if device 1 was found in ata_devchk, wait for register + * access briefly, then wait for BSY to clear. + */ + if (dev1) { + int i; + + pata_parport_dev_select(ap, 1); + + /* + * Wait for register access. Some ATAPI devices fail + * to set nsect/lbal after reset, so don't waste too + * much time on it. We're gonna wait for !BSY anyway. + */ + for (i = 0; i < 2; i++) { + u8 nsect, lbal; + + nsect = pi->proto->read_regr(pi, 0, ATA_REG_NSECT); + lbal = pi->proto->read_regr(pi, 0, ATA_REG_LBAL); + if (nsect == 1 && lbal == 1) + break; + /* give drive a breather */ + ata_msleep(ap, 50); + } + + rc = ata_sff_wait_ready(link, deadline); + if (rc) { + if (rc != -ENODEV) + return rc; + ret = rc; + } + } + + pata_parport_dev_select(ap, 0); + if (dev1) + pata_parport_dev_select(ap, 1); + if (dev0) + pata_parport_dev_select(ap, 0); + + return ret; +} + static int pata_parport_bus_softreset(struct ata_port *ap, unsigned int devmask, unsigned long deadline) { @@ -87,7 +153,7 @@ static int pata_parport_bus_softreset(struct ata_port *ap, unsigned int devmask, ap->last_ctl = ap->ctl;
/* wait the port to become ready */ - return ata_sff_wait_after_reset(&ap->link, devmask, deadline); + return pata_parport_wait_after_reset(&ap->link, devmask, deadline); }
static int pata_parport_softreset(struct ata_link *link, unsigned int *classes,