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[media] saa7164: Monitor the command bus and check for inconsistencies
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Signed-off-by: Steven Toth <stoth@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
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Steven Toth authored and Mauro Carvalho Chehab committed Oct 21, 2010
1 parent 1107237 commit 6066582
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Showing 3 changed files with 131 additions and 70 deletions.
153 changes: 87 additions & 66 deletions drivers/media/video/saa7164/saa7164-bus.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -43,17 +43,11 @@ int saa7164_bus_setup(struct saa7164_dev *dev)

b->m_dwSizeGetRing = SAA_DEVICE_BUFFERBLOCKSIZE;

b->m_pdwSetWritePos = (u32 *)((u8 *)(dev->bmmio +
((u32)dev->intfdesc.BARLocation) + (2 * sizeof(u64))));
b->m_dwSetWritePos = ((u32)dev->intfdesc.BARLocation) + (2 * sizeof(u64));
b->m_dwSetReadPos = b->m_dwSetWritePos + (1 * sizeof(u32));

b->m_pdwSetReadPos = (u32 *)((u8 *)b->m_pdwSetWritePos +
1 * sizeof(u32));

b->m_pdwGetWritePos = (u32 *)((u8 *)b->m_pdwSetWritePos +
2 * sizeof(u32));

b->m_pdwGetReadPos = (u32 *)((u8 *)b->m_pdwSetWritePos +
3 * sizeof(u32));
b->m_dwGetWritePos = b->m_dwSetWritePos + (2 * sizeof(u32));
b->m_dwGetReadPos = b->m_dwSetWritePos + (3 * sizeof(u32));

return 0;
}
Expand All @@ -71,17 +65,44 @@ void saa7164_bus_dump(struct saa7164_dev *dev)
dprintk(DBGLVL_BUS, " .m_pdwGetRing = 0x%p\n", b->m_pdwGetRing);
dprintk(DBGLVL_BUS, " .m_dwSizeGetRing = 0x%x\n", b->m_dwSizeGetRing);

dprintk(DBGLVL_BUS, " .m_pdwSetWritePos = 0x%p (0x%08x)\n",
b->m_pdwSetWritePos, *b->m_pdwSetWritePos);
dprintk(DBGLVL_BUS, " .m_dwSetReadPos = 0x%x (0x%08x)\n",
b->m_dwSetReadPos, saa7164_readl(b->m_dwSetReadPos));

dprintk(DBGLVL_BUS, " .m_dwSetWritePos = 0x%x (0x%08x)\n",
b->m_dwSetWritePos, saa7164_readl(b->m_dwSetWritePos));

dprintk(DBGLVL_BUS, " .m_pdwSetReadPos = 0x%p (0x%08x)\n",
b->m_pdwSetReadPos, *b->m_pdwSetReadPos);
dprintk(DBGLVL_BUS, " .m_dwGetReadPos = 0x%x (0x%08x)\n",
b->m_dwGetReadPos, saa7164_readl(b->m_dwGetReadPos));

dprintk(DBGLVL_BUS, " .m_pdwGetWritePos = 0x%p (0x%08x)\n",
b->m_pdwGetWritePos, *b->m_pdwGetWritePos);
dprintk(DBGLVL_BUS, " .m_dwGetWritePos = 0x%x (0x%08x)\n",
b->m_dwGetWritePos, saa7164_readl(b->m_dwGetWritePos));

dprintk(DBGLVL_BUS, " .m_pdwGetReadPos = 0x%p (0x%08x)\n",
b->m_pdwGetReadPos, *b->m_pdwGetReadPos);
}

/* Intensionally throw a BUG() if the state of the message bus looks corrupt */
void saa7164_bus_verify(struct saa7164_dev *dev)
{
tmComResBusInfo_t *b = &dev->bus;
int bug = 0, debug;

if (saa7164_readl(b->m_dwSetReadPos) > b->m_dwSizeSetRing)
bug++;

if (saa7164_readl(b->m_dwSetWritePos) > b->m_dwSizeSetRing)
bug++;

if (saa7164_readl(b->m_dwGetReadPos) > b->m_dwSizeGetRing)
bug++;

if (saa7164_readl(b->m_dwGetWritePos) > b->m_dwSizeGetRing)
bug++;

if (bug) {
debug = 0xffff; /* Ensure we get the bus dump */
saa7164_bus_dump(dev);
debug = 1024; /* Ensure we get the bus dump */
BUG();
}
}

void saa7164_bus_dumpmsg(struct saa7164_dev *dev, tmComResInfo_t* m, void *buf)
Expand Down Expand Up @@ -111,7 +132,7 @@ void saa7164_bus_dumpmsg(struct saa7164_dev *dev, tmComResInfo_t* m, void *buf)
int saa7164_bus_set(struct saa7164_dev *dev, tmComResInfo_t* msg, void *buf)
{
tmComResBusInfo_t *bus = &dev->bus;
u32 bytes_to_write, read_distance, timeout, curr_srp, curr_swp;
u32 bytes_to_write, free_write_space, timeout, curr_srp, curr_swp;
u32 new_swp, space_rem;
int ret = SAA_ERR_BAD_PARAMETER;

Expand All @@ -121,6 +142,7 @@ int saa7164_bus_set(struct saa7164_dev *dev, tmComResInfo_t* msg, void *buf)
}

dprintk(DBGLVL_BUS, "%s()\n", __func__);
saa7164_bus_verify(dev);

msg->size = cpu_to_le16(msg->size);
msg->command = cpu_to_le16(msg->command);
Expand All @@ -141,30 +163,30 @@ int saa7164_bus_set(struct saa7164_dev *dev, tmComResInfo_t* msg, void *buf)
mutex_lock(&bus->lock);

bytes_to_write = sizeof(*msg) + msg->size;
read_distance = 0;
free_write_space = 0;
timeout = SAA_BUS_TIMEOUT;
curr_srp = le32_to_cpu(*bus->m_pdwSetReadPos);
curr_swp = le32_to_cpu(*bus->m_pdwSetWritePos);
curr_srp = le32_to_cpu(saa7164_readl(bus->m_dwSetReadPos));
curr_swp = le32_to_cpu(saa7164_readl(bus->m_dwSetWritePos));

/* Deal with ring wrapping issues */
if (curr_srp > curr_swp)
/* The ring has not wrapped yet */
read_distance = curr_srp - curr_swp;
else
/* Deal with the wrapped ring */
read_distance = (curr_srp + bus->m_dwSizeSetRing) - curr_swp;
free_write_space = curr_srp - curr_swp;
else
/* The ring has not wrapped yet */
free_write_space = (curr_srp + bus->m_dwSizeSetRing) - curr_swp;

dprintk(DBGLVL_BUS, "%s() bytes_to_write = %d\n", __func__,
bytes_to_write);

dprintk(DBGLVL_BUS, "%s() read_distance = %d\n", __func__,
read_distance);
dprintk(DBGLVL_BUS, "%s() free_write_space = %d\n", __func__,
free_write_space);

dprintk(DBGLVL_BUS, "%s() curr_srp = %x\n", __func__, curr_srp);
dprintk(DBGLVL_BUS, "%s() curr_swp = %x\n", __func__, curr_swp);

/* Process the msg and write the content onto the bus */
while (bytes_to_write >= read_distance) {
while (bytes_to_write >= free_write_space) {

if (timeout-- == 0) {
printk(KERN_ERR "%s() bus timeout\n", __func__);
Expand All @@ -177,15 +199,15 @@ int saa7164_bus_set(struct saa7164_dev *dev, tmComResInfo_t* msg, void *buf)
mdelay(1);

/* Check the space usage again */
curr_srp = le32_to_cpu(*bus->m_pdwSetReadPos);
curr_srp = le32_to_cpu(saa7164_readl(bus->m_dwSetReadPos));

/* Deal with ring wrapping issues */
if (curr_srp > curr_swp)
/* Read didn't wrap around the buffer */
read_distance = curr_srp - curr_swp;
else
/* Deal with the wrapped ring */
read_distance = (curr_srp + bus->m_dwSizeSetRing) -
free_write_space = curr_srp - curr_swp;
else
/* Read didn't wrap around the buffer */
free_write_space = (curr_srp + bus->m_dwSizeSetRing) -
curr_swp;

}
Expand Down Expand Up @@ -217,28 +239,28 @@ int saa7164_bus_set(struct saa7164_dev *dev, tmComResInfo_t* msg, void *buf)
dprintk(DBGLVL_BUS, "%s() tr4\n", __func__);

/* Split the msg into pieces as the ring wraps */
memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, space_rem);
memcpy_toio(bus->m_pdwSetRing, (u8 *)msg + space_rem,
memcpy(bus->m_pdwSetRing + curr_swp, msg, space_rem);
memcpy(bus->m_pdwSetRing, (u8 *)msg + space_rem,
sizeof(*msg) - space_rem);

memcpy_toio(bus->m_pdwSetRing + sizeof(*msg) - space_rem,
memcpy(bus->m_pdwSetRing + sizeof(*msg) - space_rem,
buf, msg->size);

} else if (space_rem == sizeof(*msg)) {
dprintk(DBGLVL_BUS, "%s() tr5\n", __func__);

/* Additional data at the beginning of the ring */
memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
memcpy_toio(bus->m_pdwSetRing, buf, msg->size);
memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
memcpy(bus->m_pdwSetRing, buf, msg->size);

} else {
/* Additional data wraps around the ring */
memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
if (msg->size > 0) {
memcpy_toio(bus->m_pdwSetRing + curr_swp +
memcpy(bus->m_pdwSetRing + curr_swp +
sizeof(*msg), buf, space_rem -
sizeof(*msg));
memcpy_toio(bus->m_pdwSetRing, (u8 *)buf +
memcpy(bus->m_pdwSetRing, (u8 *)buf +
space_rem - sizeof(*msg),
bytes_to_write - space_rem);
}
Expand All @@ -250,23 +272,21 @@ int saa7164_bus_set(struct saa7164_dev *dev, tmComResInfo_t* msg, void *buf)
dprintk(DBGLVL_BUS, "%s() tr6\n", __func__);

/* The ring buffer doesn't wrap, two simple copies */
memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
memcpy_toio(bus->m_pdwSetRing + curr_swp + sizeof(*msg), buf,
memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
memcpy(bus->m_pdwSetRing + curr_swp + sizeof(*msg), buf,
msg->size);
}

dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);

/* TODO: Convert all of the direct PCI writes into
* saa7164_writel/b calls for consistency.
*/

/* Update the bus write position */
*bus->m_pdwSetWritePos = cpu_to_le32(new_swp);
saa7164_writel(bus->m_dwSetWritePos, cpu_to_le32(new_swp));
ret = SAA_OK;

out:
saa7164_bus_dump(dev);
mutex_unlock(&bus->lock);
saa7164_bus_verify(dev);
return ret;
}

Expand All @@ -288,6 +308,7 @@ int saa7164_bus_get(struct saa7164_dev *dev, tmComResInfo_t* msg, void *buf,
tmComResInfo_t msg_tmp;
int ret = SAA_ERR_BAD_PARAMETER;

saa7164_bus_verify(dev);
if (msg == 0)
return ret;

Expand All @@ -309,11 +330,10 @@ int saa7164_bus_get(struct saa7164_dev *dev, tmComResInfo_t* msg, void *buf,
/* Peek the bus to see if a msg exists, if it's not what we're expecting
* then return cleanly else read the message from the bus.
*/
curr_gwp = le32_to_cpu(*bus->m_pdwGetWritePos);
curr_grp = le32_to_cpu(*bus->m_pdwGetReadPos);
curr_gwp = le32_to_cpu(saa7164_readl(bus->m_dwGetWritePos));
curr_grp = le32_to_cpu(saa7164_readl(bus->m_dwGetReadPos));

if (curr_gwp == curr_grp) {
dprintk(DBGLVL_BUS, "%s() No message on the bus\n", __func__);
ret = SAA_ERR_EMPTY;
goto out;
}
Expand Down Expand Up @@ -343,19 +363,19 @@ int saa7164_bus_get(struct saa7164_dev *dev, tmComResInfo_t* msg, void *buf,
new_grp -= bus->m_dwSizeGetRing;
space_rem = bus->m_dwSizeGetRing - curr_grp;

memcpy_fromio(&msg_tmp, bus->m_pdwGetRing + curr_grp, space_rem);
memcpy_fromio((u8 *)&msg_tmp + space_rem, bus->m_pdwGetRing,
memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, space_rem);
memcpy((u8 *)&msg_tmp + space_rem, bus->m_pdwGetRing,
bytes_to_read - space_rem);

} else {
/* No wrapping */
memcpy_fromio(&msg_tmp, bus->m_pdwGetRing + curr_grp, bytes_to_read);
memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, bytes_to_read);
}

/* No need to update the read positions, because this was a peek */
/* If the caller specifically want to peek, return */
if (peekonly) {
memcpy_fromio(msg, &msg_tmp, sizeof(*msg));
memcpy(msg, &msg_tmp, sizeof(*msg));
goto peekout;
}

Expand Down Expand Up @@ -401,24 +421,24 @@ int saa7164_bus_get(struct saa7164_dev *dev, tmComResInfo_t* msg, void *buf,

if (space_rem < sizeof(*msg)) {
/* msg wraps around the ring */
memcpy_fromio(msg, bus->m_pdwGetRing + curr_grp, space_rem);
memcpy_fromio((u8 *)msg + space_rem, bus->m_pdwGetRing,
memcpy(msg, bus->m_pdwGetRing + curr_grp, space_rem);
memcpy((u8 *)msg + space_rem, bus->m_pdwGetRing,
sizeof(*msg) - space_rem);
if (buf)
memcpy_fromio(buf, bus->m_pdwGetRing + sizeof(*msg) -
memcpy(buf, bus->m_pdwGetRing + sizeof(*msg) -
space_rem, buf_size);

} else if (space_rem == sizeof(*msg)) {
memcpy_fromio(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
if (buf)
memcpy(buf, bus->m_pdwGetRing, buf_size);
} else {
/* Additional data wraps around the ring */
memcpy_fromio(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
if (buf) {
memcpy_fromio(buf, bus->m_pdwGetRing + curr_grp +
memcpy(buf, bus->m_pdwGetRing + curr_grp +
sizeof(*msg), space_rem - sizeof(*msg));
memcpy_fromio(buf + space_rem - sizeof(*msg),
memcpy(buf + space_rem - sizeof(*msg),
bus->m_pdwGetRing, bytes_to_read -
space_rem);
}
Expand All @@ -427,14 +447,14 @@ int saa7164_bus_get(struct saa7164_dev *dev, tmComResInfo_t* msg, void *buf,

} else {
/* No wrapping */
memcpy_fromio(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg));
if (buf)
memcpy_fromio(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg),
memcpy(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg),
buf_size);
}

/* Update the read positions, adjusting the ring */
*bus->m_pdwGetReadPos = cpu_to_le32(new_grp);
saa7164_writel(bus->m_dwGetReadPos, cpu_to_le32(new_grp));

peekout:
msg->size = le16_to_cpu(msg->size);
Expand All @@ -443,6 +463,7 @@ int saa7164_bus_get(struct saa7164_dev *dev, tmComResInfo_t* msg, void *buf,
ret = SAA_OK;
out:
mutex_unlock(&bus->lock);
saa7164_bus_verify(dev);
return ret;
}

40 changes: 40 additions & 0 deletions drivers/media/video/saa7164/saa7164-core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1122,6 +1122,46 @@ static int saa7164_proc_show(struct seq_file *m, void *v)
b = &dev->bus;
mutex_lock(&b->lock);

seq_printf(m, " .m_pdwSetWritePos = 0x%x (0x%08x)\n",
b->m_dwSetReadPos, saa7164_readl(b->m_dwSetReadPos));

seq_printf(m, " .m_pdwSetReadPos = 0x%x (0x%08x)\n",
b->m_dwSetWritePos, saa7164_readl(b->m_dwSetWritePos));

seq_printf(m, " .m_pdwGetWritePos = 0x%x (0x%08x)\n",
b->m_dwGetReadPos, saa7164_readl(b->m_dwGetReadPos));

seq_printf(m, " .m_pdwGetReadPos = 0x%x (0x%08x)\n",
b->m_dwGetWritePos, saa7164_readl(b->m_dwGetWritePos));
c = 0;
seq_printf(m, "\n Set Ring:\n");
seq_printf(m, "\n addr 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f\n");
for (i = 0; i < b->m_dwSizeSetRing; i++) {
if (c == 0)
seq_printf(m, " %04x:", i);

seq_printf(m, " %02x", *(b->m_pdwSetRing + i));

if (++c == 16) {
seq_printf(m, "\n");
c = 0;
}
}

c = 0;
seq_printf(m, "\n Get Ring:\n");
seq_printf(m, "\n addr 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f\n");
for (i = 0; i < b->m_dwSizeGetRing; i++) {
if (c == 0)
seq_printf(m, " %04x:", i);

seq_printf(m, " %02x", *(b->m_pdwGetRing + i));

if (++c == 16) {
seq_printf(m, "\n");
c = 0;
}
}

mutex_unlock(&b->lock);

Expand Down
8 changes: 4 additions & 4 deletions drivers/media/video/saa7164/saa7164-types.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -82,10 +82,10 @@ typedef struct {
u32 m_dwSizeSetRing;
u8 *m_pdwGetRing;
u32 m_dwSizeGetRing;
u32 *m_pdwSetWritePos;
u32 *m_pdwSetReadPos;
u32 *m_pdwGetWritePos;
u32 *m_pdwGetReadPos;
u32 m_dwSetWritePos;
u32 m_dwSetReadPos;
u32 m_dwGetWritePos;
u32 m_dwGetReadPos;

/* All access is protected */
struct mutex lock;
Expand Down

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