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usb: musb: host: Handle highmem in PIO mode
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In case of USB bulk transfer, when himem page
is received, the usb_sg_init function sets the
urb transfer buffer to NULL. When such URB
transfer is handled, kernel crashes in PIO mode.
Handle this by mapping the highmem buffer in PIO mode.

Signed-off-by: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
Signed-off-by: Praveena NADAHALLY <praveen.nadahally@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>
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Virupax Sadashivpetimath authored and Felipe Balbi committed Aug 7, 2012
1 parent decadac commit 8e8a551
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Showing 2 changed files with 96 additions and 5 deletions.
98 changes: 93 additions & 5 deletions drivers/usb/musb/musb_host.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -823,9 +823,28 @@ static void musb_ep_program(struct musb *musb, u8 epnum,
if (load_count) {
/* PIO to load FIFO */
qh->segsize = load_count;
musb_write_fifo(hw_ep, load_count, buf);
if (!buf) {
sg_miter_start(&qh->sg_miter, urb->sg, 1,
SG_MITER_ATOMIC
| SG_MITER_FROM_SG);
if (!sg_miter_next(&qh->sg_miter)) {
dev_err(musb->controller,
"error: sg"
"list empty\n");
sg_miter_stop(&qh->sg_miter);
goto finish;
}
buf = qh->sg_miter.addr + urb->sg->offset +
urb->actual_length;
load_count = min_t(u32, load_count,
qh->sg_miter.length);
musb_write_fifo(hw_ep, load_count, buf);
qh->sg_miter.consumed = load_count;
sg_miter_stop(&qh->sg_miter);
} else
musb_write_fifo(hw_ep, load_count, buf);
}

finish:
/* re-enable interrupt */
musb_writew(mbase, MUSB_INTRTXE, int_txe);

Expand Down Expand Up @@ -1193,6 +1212,7 @@ void musb_host_tx(struct musb *musb, u8 epnum)
void __iomem *mbase = musb->mregs;
struct dma_channel *dma;
bool transfer_pending = false;
static bool use_sg;

musb_ep_select(mbase, epnum);
tx_csr = musb_readw(epio, MUSB_TXCSR);
Expand Down Expand Up @@ -1247,6 +1267,7 @@ void musb_host_tx(struct musb *musb, u8 epnum)
return;
}

done:
if (status) {
if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
dma->status = MUSB_DMA_STATUS_CORE_ABORT;
Expand Down Expand Up @@ -1416,9 +1437,38 @@ void musb_host_tx(struct musb *musb, u8 epnum)
length = qh->maxpacket;
/* Unmap the buffer so that CPU can use it */
usb_hcd_unmap_urb_for_dma(musb_to_hcd(musb), urb);
musb_write_fifo(hw_ep, length, urb->transfer_buffer + offset);

/*
* We need to map sg if the transfer_buffer is
* NULL.
*/
if (!urb->transfer_buffer)
use_sg = true;

if (use_sg) {
/* sg_miter_start is already done in musb_ep_program */
if (!sg_miter_next(&qh->sg_miter)) {
dev_err(musb->controller, "error: sg list empty\n");
sg_miter_stop(&qh->sg_miter);
status = -EINVAL;
goto done;
}
urb->transfer_buffer = qh->sg_miter.addr;
length = min_t(u32, length, qh->sg_miter.length);
musb_write_fifo(hw_ep, length, urb->transfer_buffer);
qh->sg_miter.consumed = length;
sg_miter_stop(&qh->sg_miter);
} else {
musb_write_fifo(hw_ep, length, urb->transfer_buffer + offset);
}

qh->segsize = length;

if (use_sg) {
if (offset + length >= urb->transfer_buffer_length)
use_sg = false;
}

musb_ep_select(mbase, epnum);
musb_writew(epio, MUSB_TXCSR,
MUSB_TXCSR_H_WZC_BITS | MUSB_TXCSR_TXPKTRDY);
Expand Down Expand Up @@ -1482,6 +1532,8 @@ void musb_host_rx(struct musb *musb, u8 epnum)
bool done = false;
u32 status;
struct dma_channel *dma;
static bool use_sg;
unsigned int sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;

musb_ep_select(mbase, epnum);

Expand Down Expand Up @@ -1796,10 +1848,43 @@ void musb_host_rx(struct musb *musb, u8 epnum)
#endif /* Mentor DMA */

if (!dma) {
unsigned int received_len;

/* Unmap the buffer so that CPU can use it */
usb_hcd_unmap_urb_for_dma(musb_to_hcd(musb), urb);
done = musb_host_packet_rx(musb, urb,
epnum, iso_err);

/*
* We need to map sg if the transfer_buffer is
* NULL.
*/
if (!urb->transfer_buffer) {
use_sg = true;
sg_miter_start(&qh->sg_miter, urb->sg, 1,
sg_flags);
}

if (use_sg) {
if (!sg_miter_next(&qh->sg_miter)) {
dev_err(musb->controller, "error: sg list empty\n");
sg_miter_stop(&qh->sg_miter);
status = -EINVAL;
done = true;
goto finish;
}
urb->transfer_buffer = qh->sg_miter.addr;
received_len = urb->actual_length;
qh->offset = 0x0;
done = musb_host_packet_rx(musb, urb, epnum,
iso_err);
/* Calculate the number of bytes received */
received_len = urb->actual_length -
received_len;
qh->sg_miter.consumed = received_len;
sg_miter_stop(&qh->sg_miter);
} else {
done = musb_host_packet_rx(musb, urb,
epnum, iso_err);
}
dev_dbg(musb->controller, "read %spacket\n", done ? "last " : "");
}
}
Expand All @@ -1808,6 +1893,9 @@ void musb_host_rx(struct musb *musb, u8 epnum)
urb->actual_length += xfer_len;
qh->offset += xfer_len;
if (done) {
if (use_sg)
use_sg = false;

if (urb->status == -EINPROGRESS)
urb->status = status;
musb_advance_schedule(musb, urb, hw_ep, USB_DIR_IN);
Expand Down
3 changes: 3 additions & 0 deletions drivers/usb/musb/musb_host.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,8 @@
#ifndef _MUSB_HOST_H
#define _MUSB_HOST_H

#include <linux/scatterlist.h>

static inline struct usb_hcd *musb_to_hcd(struct musb *musb)
{
return container_of((void *) musb, struct usb_hcd, hcd_priv);
Expand Down Expand Up @@ -71,6 +73,7 @@ struct musb_qh {
u16 maxpacket;
u16 frame; /* for periodic schedule */
unsigned iso_idx; /* in urb->iso_frame_desc[] */
struct sg_mapping_iter sg_miter; /* for highmem in PIO mode */
};

/* map from control or bulk queue head to the first qh on that ring */
Expand Down

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