ioat: preserve chanctrl bits when re-arming interrupts

The register write in ioat_dma_cleanup_tasklet is unfortunate in two
ways:
1/ It clears the extra 'enable' bits that we set at alloc_chan_resources time
2/ It gives the impression that it disables interrupts when it is in
   fact re-arming interrupts

[ Impact: fix, persist the value of the chanctrl register when re-arming ]

Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
index 5173ba9..6dd0af1 100644 (file)
--- a/drivers/dma/ioat/dma.c
+++ b/drivers/dma/ioat/dma.c
@@ -452,7 +452,6 @@ static int ioat1_dma_alloc_chan_resources(struct dma_chan *c)
        struct ioat_dma_chan *ioat = to_ioat_chan(c);
        struct ioat_chan_common *chan = &ioat->base;
        struct ioat_desc_sw *desc;
-       u16 chanctrl;
        u32 chanerr;
        int i;
        LIST_HEAD(tmp_list);
@@ -462,10 +461,7 @@ static int ioat1_dma_alloc_chan_resources(struct dma_chan *c)
                return ioat->desccount;
 
        /* Setup register to interrupt and write completion status on error */
-       chanctrl = IOAT_CHANCTRL_ERR_INT_EN |
-               IOAT_CHANCTRL_ANY_ERR_ABORT_EN |
-               IOAT_CHANCTRL_ERR_COMPLETION_EN;
-       writew(chanctrl, chan->reg_base + IOAT_CHANCTRL_OFFSET);
+       writew(IOAT_CHANCTRL_RUN, chan->reg_base + IOAT_CHANCTRL_OFFSET);
 
        chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
        if (chanerr) {
@@ -672,9 +668,9 @@ ioat1_dma_prep_memcpy(struct dma_chan *c, dma_addr_t dma_dest,
 static void ioat1_cleanup_tasklet(unsigned long data)
 {
        struct ioat_dma_chan *chan = (void *)data;
+
        ioat1_cleanup(chan);
-       writew(IOAT_CHANCTRL_INT_DISABLE,
-              chan->base.reg_base + IOAT_CHANCTRL_OFFSET);
+       writew(IOAT_CHANCTRL_RUN, chan->base.reg_base + IOAT_CHANCTRL_OFFSET);
 }
 
 static void ioat_unmap(struct pci_dev *pdev, dma_addr_t addr, size_t len,

diff --git a/drivers/dma/ioat/dma_v2.c b/drivers/dma/ioat/dma_v2.c
index 137cf87..2f34f29 100644 (file)
--- a/drivers/dma/ioat/dma_v2.c
+++ b/drivers/dma/ioat/dma_v2.c
@@ -341,8 +341,7 @@ static void ioat2_cleanup_tasklet(unsigned long data)
        struct ioat2_dma_chan *ioat = (void *) data;
 
        ioat2_cleanup(ioat);
-       writew(IOAT_CHANCTRL_INT_DISABLE,
-              ioat->base.reg_base + IOAT_CHANCTRL_OFFSET);
+       writew(IOAT_CHANCTRL_RUN, ioat->base.reg_base + IOAT_CHANCTRL_OFFSET);
 }
 
 /**
@@ -454,7 +453,6 @@ static int ioat2_alloc_chan_resources(struct dma_chan *c)
        struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
        struct ioat_chan_common *chan = &ioat->base;
        struct ioat_ring_ent **ring;
-       u16 chanctrl;
        u32 chanerr;
        int descs;
        int i;
@@ -464,9 +462,7 @@ static int ioat2_alloc_chan_resources(struct dma_chan *c)
                return 1 << ioat->alloc_order;
 
        /* Setup register to interrupt and write completion status on error */
-       chanctrl = IOAT_CHANCTRL_ERR_INT_EN | IOAT_CHANCTRL_ANY_ERR_ABORT_EN |
-                  IOAT_CHANCTRL_ERR_COMPLETION_EN;
-       writew(chanctrl, chan->reg_base + IOAT_CHANCTRL_OFFSET);
+       writew(IOAT_CHANCTRL_RUN, chan->reg_base + IOAT_CHANCTRL_OFFSET);
 
        chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
        if (chanerr) {

diff --git a/drivers/dma/ioat/registers.h b/drivers/dma/ioat/registers.h
index a83c733..4380f6f 100644 (file)
--- a/drivers/dma/ioat/registers.h
+++ b/drivers/dma/ioat/registers.h
@@ -75,7 +75,11 @@
 #define IOAT_CHANCTRL_ERR_INT_EN               0x0010
 #define IOAT_CHANCTRL_ANY_ERR_ABORT_EN         0x0008
 #define IOAT_CHANCTRL_ERR_COMPLETION_EN                0x0004
-#define IOAT_CHANCTRL_INT_DISABLE              0x0001
+#define IOAT_CHANCTRL_INT_REARM                        0x0001
+#define IOAT_CHANCTRL_RUN                      (IOAT_CHANCTRL_INT_REARM |\
+                                                IOAT_CHANCTRL_ERR_COMPLETION_EN |\
+                                                IOAT_CHANCTRL_ANY_ERR_ABORT_EN |\
+                                                IOAT_CHANCTRL_ERR_INT_EN)
 
 #define IOAT_DMA_COMP_OFFSET                   0x02    /* 16-bit DMA channel compatibility */
 #define IOAT_DMA_COMP_V1                       0x0001  /* Compatibility with DMA version 1 */