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Find (hopefully) best interrupt pipe bandwidth allocation

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This commit is contained in:
PaulStoffregen 2017-02-14 04:19:20 -08:00
parent 4b4ce19dc6
commit 97f728e83c
1 changed files with 111 additions and 22 deletions
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133
ehci.cpp
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@ -27,13 +27,14 @@
#define PERIODIC_LIST_SIZE 32
static uint32_t periodictable[PERIODIC_LIST_SIZE] __attribute__ ((aligned(4096), used));
static uint8_t port_state;
static uint8_t uframe_bandwidth[PERIODIC_LIST_SIZE*8];
static uint8_t port_state;
#define PORT_STATE_DISCONNECTED 0
#define PORT_STATE_DEBOUNCE 1
#define PORT_STATE_RESET 2
#define PORT_STATE_RECOVERY 3
#define PORT_STATE_ACTIVE 4
static Device_t *rootdev=NULL;
static Device_t *rootdev=NULL;
static Transfer_t *async_followup_first=NULL;
static Transfer_t *async_followup_last=NULL;
static Transfer_t *periodic_followup_first=NULL;
@ -123,6 +124,7 @@ void USBHost::begin()
for (int i=0; i < 32; i++) {
periodictable[i] = 1;
}
memset(uframe_bandwidth, 0, sizeof(uframe_bandwidth));
port_state = PORT_STATE_DISCONNECTED;
USBHS_USB_SBUSCFG = 1; // System Bus Interface Configuration
@ -703,6 +705,30 @@ static void remove_from_periodic_followup_list(Transfer_t *transfer)
}
static uint32_t max4(uint32_t n1, uint32_t n2, uint32_t n3, uint32_t n4)
{
if (n1 > n2) {
// can't be n2
if (n1 > n3) {
// can't be n3
if (n1 > n4) return n1;
} else {
// can't be n1
if (n3 > n4) return n3;
}
} else {
// can't be n1
if (n2 > n3) {
// can't be n3
if (n2 > n4) return n2;
} else {
// can't be n2
if (n3 > n4) return n3;
}
}
return n4;
}
// Allocate bandwidth for an interrupt pipe. Given the packet size
// and other parameters, find the best place to schedule this pipe.
// Returns true if enough bandwidth is available, and the best
@ -718,32 +744,95 @@ static void remove_from_periodic_followup_list(Transfer_t *transfer)
// cmask: [out] Complete Mask
//
static bool allocate_interrupt_pipe_bandwidth(uint32_t speed, uint32_t maxlen,
uint32_t interval, uint32_t direction, uint32_t *offset, uint32_t *smask,
uint32_t *cmask)
uint32_t interval, uint32_t direction, uint32_t *offset_out,
uint32_t *smask_out, uint32_t *cmask_out)
{
// TODO: actual bandwidth planning needs to go here... but for
// now we'll just always pile up everything at the same offset
// and same microframe schedule for split transactions, without
// even the slighest check whether it all fits.
Serial.println("allocate_interrupt_pipe_bandwidth");
maxlen = (maxlen * 76459) >> 16; // worst case bit stuffing
if (speed == 2) {
// high speed 480 Mbit/sec
if (interval == 1) {
*smask = 0xFF;
} else if (interval == 2) {
*smask = 0x55;
} else if (interval <= 4) {
*smask = 0x11;
} else {
*smask = 0x01;
uint32_t stime = (55 + 32 + maxlen) >> 5;
uint32_t min_offset = 0xFFFFFFFF;
uint32_t min_bw = 0xFFFFFFFF;
for (uint32_t offset=0; offset < interval; offset++) {
uint32_t max_bw = 0;
for (uint32_t i=offset; i < PERIODIC_LIST_SIZE*8; i += interval) {
uint32_t bw = uframe_bandwidth[i] + stime;
if (bw > max_bw) max_bw = bw;
}
if (max_bw < min_bw) {
min_bw = max_bw;
min_offset = offset;
}
}
*cmask = 0;
*offset = 0;
Serial.print(" min_bw = ");
Serial.print(min_bw);
Serial.print(", at offset = ");
Serial.println(min_offset);
if (min_bw > 187) return false;
for (uint32_t i=min_offset; i < PERIODIC_LIST_SIZE*8; i += interval) {
uframe_bandwidth[i] += stime;
}
*offset_out = min_offset >> 3;
if (interval == 1) {
*smask_out = 0xFF;
} else if (interval == 2) {
*smask_out = 0x55 << (min_offset & 1);
} else if (interval <= 4) {
*smask_out = 0x11 << (min_offset & 3);
} else {
*smask_out = 0x01 << (min_offset & 7);
}
*cmask_out = 0;
} else {
// full speed 12 Mbit/sec or low speed 1.5 Mbit/sec
*smask = 0x01;
*cmask = 0x3C;
*offset = 0;
uint32_t stime, ctime;
if (direction == 0) {
stime = (100 + 32 + maxlen) >> 5;
ctime = (55 + 32) >> 5;
} else {
stime = (40 + 32) >> 5;
ctime = (70 + 32 + maxlen) >> 5;
}
interval = interval >> 3; // can't be zero, earlier check for interval >= 8
uint32_t min_shift = 0;
uint32_t min_offset = 0xFFFFFFFF;
uint32_t min_bw = 0xFFFFFFFF;
for (uint32_t offset=0; offset < interval; offset++) {
uint32_t max_bw = 0;
for (uint32_t i=offset; i < PERIODIC_LIST_SIZE; i += interval) {
for (uint32_t j=0; j <= 3; j++) { // max 3 without FSTN
uint32_t n = (i << 3) + j;
uint32_t bw1 = uframe_bandwidth[n+0] + stime;
uint32_t bw2 = uframe_bandwidth[n+2] + ctime;
uint32_t bw3 = uframe_bandwidth[n+3] + ctime;
uint32_t bw4 = uframe_bandwidth[n+4] + ctime;
max_bw = max4(bw1, bw2, bw3, bw4);
if (max_bw < min_bw) {
min_bw = max_bw;
min_offset = i;
min_shift = j;
}
}
}
}
Serial.print(" min_bw = ");
Serial.println(min_bw);
Serial.print(", at offset = ");
Serial.print(min_offset);
Serial.print(", shift= ");
Serial.println(min_shift);
if (min_bw > 187) return false;
for (uint32_t i=min_offset; i < PERIODIC_LIST_SIZE; i += interval) {
uint32_t n = (i << 3) + min_shift;
uframe_bandwidth[n+0] += stime;
uframe_bandwidth[n+2] += ctime;
uframe_bandwidth[n+3] += ctime;
uframe_bandwidth[n+4] += ctime;
}
*smask_out = 0x01 << min_shift;
*cmask_out = 0x1C << min_shift;
*offset_out = min_offset;
}
return true;
}