ravb: do not write 1 to reserved bits

EtherAVB hardware requires 0 to be written to status register bits in
order to clear them, however, care must be taken not to:

1. Clear other bits, by writing zero to them
2. Write one to reserved bits

This patch corrects the ravb driver with respect to the second point above.
This is done by defining reserved bit masks for the affected registers and,
after auditing the code, ensure all sites that may write a one to a
reserved bit use are suitably masked.

Signed-off-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
index 1470fc12282b255181838457ff6a07a362e3e321..9b6bf557a2f5ffde5fe405f17e3307014f0c6a05 100644 (file)
--- a/drivers/net/ethernet/renesas/ravb.h
+++ b/drivers/net/ethernet/renesas/ravb.h
@@ -428,6 +428,7 @@ enum EIS_BIT {
        EIS_CULF1       = 0x00000080,
        EIS_TFFF        = 0x00000100,
        EIS_QFS         = 0x00010000,
+       EIS_RESERVED    = (GENMASK(31, 17) | GENMASK(15, 11)),
 };
 
 /* RIC0 */
@@ -472,6 +473,7 @@ enum RIS0_BIT {
        RIS0_FRF15      = 0x00008000,
        RIS0_FRF16      = 0x00010000,
        RIS0_FRF17      = 0x00020000,
+       RIS0_RESERVED   = GENMASK(31, 18),
 };
 
 /* RIC1 */
@@ -528,6 +530,7 @@ enum RIS2_BIT {
        RIS2_QFF16      = 0x00010000,
        RIS2_QFF17      = 0x00020000,
        RIS2_RFFF       = 0x80000000,
+       RIS2_RESERVED   = GENMASK(30, 18),
 };
 
 /* TIC */
@@ -544,6 +547,7 @@ enum TIS_BIT {
        TIS_FTF1        = 0x00000002,   /* Undocumented? */
        TIS_TFUF        = 0x00000100,
        TIS_TFWF        = 0x00000200,
+       TIS_RESERVED    = (GENMASK(31, 20) | GENMASK(15, 12) | GENMASK(7, 4))
 };
 
 /* ISS */
@@ -617,6 +621,7 @@ enum GIC_BIT {
 enum GIS_BIT {
        GIS_PTCF        = 0x00000001,   /* Undocumented? */
        GIS_PTMF        = 0x00000004,
+       GIS_RESERVED    = GENMASK(15, 10),
 };
 
 /* GIE (R-Car Gen3 only) */

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index aff5516b781e27067efc9c1cca19f11bea19dd19..d6f753925352d41758945aca8d5ef6340cceee9a 100644 (file)
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -739,10 +739,11 @@ static void ravb_error_interrupt(struct net_device *ndev)
        u32 eis, ris2;
 
        eis = ravb_read(ndev, EIS);
-       ravb_write(ndev, ~EIS_QFS, EIS);
+       ravb_write(ndev, ~(EIS_QFS | EIS_RESERVED), EIS);
        if (eis & EIS_QFS) {
                ris2 = ravb_read(ndev, RIS2);
-               ravb_write(ndev, ~(RIS2_QFF0 | RIS2_RFFF), RIS2);
+               ravb_write(ndev, ~(RIS2_QFF0 | RIS2_RFFF | RIS2_RESERVED),
+                          RIS2);
 
                /* Receive Descriptor Empty int */
                if (ris2 & RIS2_QFF0)
@@ -795,7 +796,7 @@ static bool ravb_timestamp_interrupt(struct net_device *ndev)
        u32 tis = ravb_read(ndev, TIS);
 
        if (tis & TIS_TFUF) {
-               ravb_write(ndev, ~TIS_TFUF, TIS);
+               ravb_write(ndev, ~(TIS_TFUF | TIS_RESERVED), TIS);
                ravb_get_tx_tstamp(ndev);
                return true;
        }
@@ -930,7 +931,7 @@ static int ravb_poll(struct napi_struct *napi, int budget)
                /* Processing RX Descriptor Ring */
                if (ris0 & mask) {
                        /* Clear RX interrupt */
-                       ravb_write(ndev, ~mask, RIS0);
+                       ravb_write(ndev, ~(mask | RIS0_RESERVED), RIS0);
                        if (ravb_rx(ndev, &quota, q))
                                goto out;
                }
@@ -938,7 +939,7 @@ static int ravb_poll(struct napi_struct *napi, int budget)
                if (tis & mask) {
                        spin_lock_irqsave(&priv->lock, flags);
                        /* Clear TX interrupt */
-                       ravb_write(ndev, ~mask, TIS);
+                       ravb_write(ndev, ~(mask | TIS_RESERVED), TIS);
                        ravb_tx_free(ndev, q, true);
                        netif_wake_subqueue(ndev, q);
                        mmiowb();

diff --git a/drivers/net/ethernet/renesas/ravb_ptp.c b/drivers/net/ethernet/renesas/ravb_ptp.c
index 0721b5c35d91d613256159763c7e4430247da3af..dce2a40a31e336d6a45b8e393a384787743859f9 100644 (file)
--- a/drivers/net/ethernet/renesas/ravb_ptp.c
+++ b/drivers/net/ethernet/renesas/ravb_ptp.c
@@ -315,7 +315,7 @@ void ravb_ptp_interrupt(struct net_device *ndev)
                }
        }
 
-       ravb_write(ndev, ~gis, GIS);
+       ravb_write(ndev, ~(gis | GIS_RESERVED), GIS);
 }
 
 void ravb_ptp_init(struct net_device *ndev, struct platform_device *pdev)