On 3/9/06, Adrian Bunk <bunk@xxxxxxxxx> wrote:
> The Coverity checker found this inconsistent NULL checking recently
> introduced by the following commit:
>
> 2ae5b30ff08cee422c7f6388a759f7
> Author: Dan Williams <dan.j.williams@xxxxxxxxx>
> [PATCH] Necessary evil to get sata_vsc to initialize with Intel iq3124h hba
>
>
> In function vsc_sata_interrupt():
>
> err_status = ap ? vsc_sata_scr_read(ap, SCR_ERROR) : 0;
> vsc_sata_scr_write(ap, SCR_ERROR, err_status);
>
>
> vsc_sata_scr_write() always dereferences ap
> (since SCR_ERROR < SCR_CONTROL).
>
> Checking for NULL in one line and unconditionally dereferencing the
> variable in the next line can't be right.
>
The attached patch cleans up the code, and adds GD31244 to the driver
description in drivers/scsi/Kconfig.
Dan
diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 3c606cf..d01edc3 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -587,10 +587,10 @@ config SCSI_SATA_VIA
If unsure, say N.
config SCSI_SATA_VITESSE
- tristate "VITESSE VSC-7174 SATA support"
+ tristate "VITESSE VSC-7174 / INTEL 31244 SATA support"
depends on SCSI_SATA && PCI
help
- This option enables support for Vitesse VSC7174 Serial ATA.
+ This option enables support for Vitesse VSC7174 and Intel 31244 Serial ATA.
If unsure, say N.
diff --git a/drivers/scsi/sata_vsc.c b/drivers/scsi/sata_vsc.c
index e484e8d..5b65fc7 100644
--- a/drivers/scsi/sata_vsc.c
+++ b/drivers/scsi/sata_vsc.c
@@ -82,17 +82,20 @@
#define VSC_SATA_PORT_OFFSET 0x200
/* Error interrupt status bit offsets */
-#define VSC_SATA_INT_ERROR_E_OFFSET 2
-#define VSC_SATA_INT_ERROR_P_OFFSET 4
-#define VSC_SATA_INT_ERROR_T_OFFSET 5
-#define VSC_SATA_INT_ERROR_M_OFFSET 1
+#define VSC_SATA_INT_ERROR_CRC (1 << 6)
+#define VSC_SATA_INT_ERROR_T (1 << 5)
+#define VSC_SATA_INT_ERROR_P (1 << 4)
+#define VSC_SATA_INT_ERROR_R (1 << 3)
+#define VSC_SATA_INT_ERROR_E (1 << 2)
+#define VSC_SATA_INT_ERROR_M (1 << 1)
+#define VSC_SATA_INT_PHY_CHANGE (1 << 0)
+#define VSC_SATA_INT_ERROR (VSC_SATA_INT_ERROR_CRC + VSC_SATA_INT_ERROR_T + \
+ VSC_SATA_INT_ERROR_P + VSC_SATA_INT_ERROR_R + \
+ VSC_SATA_INT_ERROR_E + VSC_SATA_INT_ERROR_M + \
+ VSC_SATA_INT_PHY_CHANGE)
+
#define is_vsc_sata_int_err(port_idx, int_status) \
- (int_status & ((1 << (VSC_SATA_INT_ERROR_E_OFFSET + (8 * port_idx))) | \
- (1 << (VSC_SATA_INT_ERROR_P_OFFSET + (8 * port_idx))) | \
- (1 << (VSC_SATA_INT_ERROR_T_OFFSET + (8 * port_idx))) | \
- (1 << (VSC_SATA_INT_ERROR_M_OFFSET + (8 * port_idx))) \
- )\
- )
+ (int_status & (VSC_SATA_INT_ERROR << (8 * port_idx)))
static u32 vsc_sata_scr_read (struct ata_port *ap, unsigned int sc_reg)
@@ -215,14 +218,6 @@ static irqreturn_t vsc_sata_interrupt (i
ap = host_set->ports[i];
- if (is_vsc_sata_int_err(i, int_status)) {
- u32 err_status;
- printk(KERN_DEBUG "%s: ignoring interrupt(s)\n", __FUNCTION__);
- err_status = ap ? vsc_sata_scr_read(ap, SCR_ERROR) : 0;
- vsc_sata_scr_write(ap, SCR_ERROR, err_status);
- handled++;
- }
-
if (ap && !(ap->flags &
(ATA_FLAG_PORT_DISABLED|ATA_FLAG_NOINTR))) {
struct ata_queued_cmd *qc;
@@ -230,12 +225,26 @@ static irqreturn_t vsc_sata_interrupt (i
qc = ata_qc_from_tag(ap, ap->active_tag);
if (qc && (!(qc->tf.ctl & ATA_NIEN))) {
handled += ata_host_intr(ap, qc);
- } else {
- printk(KERN_DEBUG "%s: ignoring interrupt(s)\n", __FUNCTION__);
+ } else if (is_vsc_sata_int_err(i, int_status)) {
+ /*
+ * On some chips (i.e. Intel 31244), an error
+ * interrupt will sneak in at initialization
+ * time (phy state changes). Clearing the SCR
+ * error register is not required, but it prevents
+ * the phy state change interrupts from recurring
+ * later.
+ */
+ u32 err_status;
+ err_status = vsc_sata_scr_read(ap, SCR_ERROR);
+ printk(KERN_DEBUG "%s: clearing interrupt, "
+ "status %x; sata err status %x\n",
+ __FUNCTION__,
+ int_status, err_status);
+ vsc_sata_scr_write(ap, SCR_ERROR, err_status);
+ /* Clear interrupt status */
ata_chk_status(ap);
handled++;
}
-
}
}
}
