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authorMagnus Damm <damm@opensource.se>2009-09-30 11:57:24 +0000
committerPaul Mundt <lethal@linux-sh.org>2009-10-06 10:59:03 +0900
commit59c82d12aa898c2f373b7e44bdea0b7c762ceccc (patch)
tree711b5b17b4a1f3c7790d3793bad27beb141dfe42 /drivers/usb
parent9c472c4dd892b75c19d13b8fdbe35fbb09bdbd0d (diff)
usb: r8a66597-udc unaligned fifo fix
Rework the r8a66597-udc fifo code to avoid unaligned accesses. Without this patch unaligned exceptions will degrade the USB performance. The exceptions come from the fact that the usb fifo data buffers may be misaligned. This patch updates the fifo access code to only use insl()/outsl() and insw()/outsw() in the case of properly aligned data buffers. The fallback case is that inl()/inw() are used for misaligned buffer reads together with outb() that is used for misaligned buffer writes. Signed-off-by: Magnus Damm <damm@opensource.se> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/gadget/r8a66597-udc.h105
1 files changed, 62 insertions, 43 deletions
diff --git a/drivers/usb/gadget/r8a66597-udc.h b/drivers/usb/gadget/r8a66597-udc.h
index 03087e7b9190..9a537aa07968 100644
--- a/drivers/usb/gadget/r8a66597-udc.h
+++ b/drivers/usb/gadget/r8a66597-udc.h
@@ -131,31 +131,48 @@ static inline u16 r8a66597_read(struct r8a66597 *r8a66597, unsigned long offset)
}
static inline void r8a66597_read_fifo(struct r8a66597 *r8a66597,
- unsigned long offset, u16 *buf,
+ unsigned long offset,
+ unsigned char *buf,
int len)
{
+ unsigned long fifoaddr = r8a66597->reg + offset;
+ unsigned int data;
+ int i;
+
if (r8a66597->pdata->on_chip) {
- unsigned long fifoaddr = r8a66597->reg + offset;
- unsigned long count;
- union {
- unsigned long dword;
- unsigned char byte[4];
- } data;
- unsigned char *pb;
- int i;
-
- count = len / 4;
- insl(fifoaddr, buf, count);
-
- if (len & 0x00000003) {
- data.dword = inl(fifoaddr);
- pb = (unsigned char *)buf + count * 4;
- for (i = 0; i < (len & 0x00000003); i++)
- pb[i] = data.byte[i];
+ /* 32-bit accesses for on_chip controllers */
+
+ /* aligned buf case */
+ if (len >= 4 && !((unsigned long)buf & 0x03)) {
+ insl(fifoaddr, buf, len / 4);
+ buf += len & ~0x03;
+ len &= 0x03;
+ }
+
+ /* unaligned buf case */
+ for (i = 0; i < len; i++) {
+ if (!(i & 0x03))
+ data = inl(fifoaddr);
+
+ buf[i] = (data >> ((i & 0x03) * 8)) & 0xff;
}
} else {
- len = (len + 1) / 2;
- insw(r8a66597->reg + offset, buf, len);
+ /* 16-bit accesses for external controllers */
+
+ /* aligned buf case */
+ if (len >= 2 && !((unsigned long)buf & 0x01)) {
+ insw(fifoaddr, buf, len / 2);
+ buf += len & ~0x01;
+ len &= 0x01;
+ }
+
+ /* unaligned buf case */
+ for (i = 0; i < len; i++) {
+ if (!(i & 0x01))
+ data = inw(fifoaddr);
+
+ buf[i] = (data >> ((i & 0x01) * 8)) & 0xff;
+ }
}
}
@@ -166,38 +183,40 @@ static inline void r8a66597_write(struct r8a66597 *r8a66597, u16 val,
}
static inline void r8a66597_write_fifo(struct r8a66597 *r8a66597,
- unsigned long offset, u16 *buf,
+ unsigned long offset,
+ unsigned char *buf,
int len)
{
unsigned long fifoaddr = r8a66597->reg + offset;
+ int adj = 0;
+ int i;
if (r8a66597->pdata->on_chip) {
- unsigned long count;
- unsigned char *pb;
- int i;
-
- count = len / 4;
- outsl(fifoaddr, buf, count);
-
- if (len & 0x00000003) {
- pb = (unsigned char *)buf + count * 4;
- for (i = 0; i < (len & 0x00000003); i++) {
- if (r8a66597_read(r8a66597, CFIFOSEL) & BIGEND)
- outb(pb[i], fifoaddr + i);
- else
- outb(pb[i], fifoaddr + 3 - i);
- }
+ /* 32-bit access only if buf is 32-bit aligned */
+ if (len >= 4 && !((unsigned long)buf & 0x03)) {
+ outsl(fifoaddr, buf, len / 4);
+ buf += len & ~0x03;
+ len &= 0x03;
}
} else {
- int odd = len & 0x0001;
-
- len = len / 2;
- outsw(fifoaddr, buf, len);
- if (unlikely(odd)) {
- buf = &buf[len];
- outb((unsigned char)*buf, fifoaddr);
+ /* 16-bit access only if buf is 16-bit aligned */
+ if (len >= 2 && !((unsigned long)buf & 0x01)) {
+ outsw(fifoaddr, buf, len / 2);
+ buf += len & ~0x01;
+ len &= 0x01;
}
}
+
+ /* adjust fifo address in the little endian case */
+ if (!(r8a66597_read(r8a66597, CFIFOSEL) & BIGEND)) {
+ if (r8a66597->pdata->on_chip)
+ adj = 0x03; /* 32-bit wide */
+ else
+ adj = 0x01; /* 16-bit wide */
+ }
+
+ for (i = 0; i < len; i++)
+ outb(buf[i], fifoaddr + adj - (i & adj));
}
static inline void r8a66597_mdfy(struct r8a66597 *r8a66597,