[PATCH 1/4] usb: renesas_usbhs: fix the behavior of some usbhs_pkt_handle

[Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>]

Some gadget drivers will call usb_ep_queue() more than once before
the first queue doesn't finish. However, this driver didn't handle
it correctly. So, this patch fixes the behavior of some
usbhs_pkt_handle using the "running" flag. Otherwise, the oops below
happens if we use g_ncm driver and when the "iperf -u -c host -b 200M"
is running.

Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = c0004000
[00000000] *pgd\0000000
Internal error: Oops: 80000007 [#1] SMP ARM
Modules linked in: usb_f_ncm g_ncm libcomposite u_ether
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        W      3.17.0-rc1-00008-g8b2be8a-dirty #20
task: c051c7e0 ti: c0512000 task.ti: c0512000
PC is at 0x0
LR is at usbhsf_pkt_handler+0xa8/0x114
pc : [<00000000>]    lr : [<c0278fb4>]    psr: 60000193
sp : c0513ce8  ip : c0513c58  fp : c0513d24
r10: 00000001  r9 : 00000193  r8 : eebec4a0
r7 : eebec410  r6 : eebe0c6c  r5 : 00000000  r4 : ee4a2774
r3 : 00000000  r2 : ee251e00  r1 : c0513cf4  r0 : ee4a2774

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
 drivers/usb/renesas_usbhs/fifo.c |   25 ++++++++++++++++++++++++-
 drivers/usb/renesas_usbhs/pipe.c |   13 +++++++++++++
 drivers/usb/renesas_usbhs/pipe.h |    4 ++++
 3 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/renesas_usbhs/fifo.c b/drivers/usb/renesas_usbhs/fifo.c
index 4fd3653..3efece3 100644
--- a/drivers/usb/renesas_usbhs/fifo.c
+++ b/drivers/usb/renesas_usbhs/fifo.c
@@ -544,6 +544,7 @@ static int usbhsf_pio_try_push(struct usbhs_pkt *pkt, int *is_done)
 		usbhsf_send_terminator(pipe, fifo);

 	usbhsf_tx_irq_ctrl(pipe, !*is_done);
+	usbhs_pipe_running(pipe, !*is_done);
 	usbhs_pipe_enable(pipe);

 	dev_dbg(dev, "  send %d (%d/ %d/ %d/ %d)\n",
@@ -570,12 +571,21 @@ usbhs_fifo_write_busy:
 	 * retry in interrupt
 	 */
 	usbhsf_tx_irq_ctrl(pipe, 1);
+	usbhs_pipe_running(pipe, 1);

 	return ret;
 }

+static int usbhsf_pio_prepare_push(struct usbhs_pkt *pkt, int *is_done)
+{
+	if (usbhs_pipe_is_running(pkt->pipe))
+		return 0;
+
+	return usbhsf_pio_try_push(pkt, is_done);
+}
+
 struct usbhs_pkt_handle usbhs_fifo_pio_push_handler = {
-	.prepare = usbhsf_pio_try_push,
+	.prepare = usbhsf_pio_prepare_push,
 	.try_run = usbhsf_pio_try_push,
 };

@@ -589,6 +599,9 @@ static int usbhsf_prepare_pop(struct usbhs_pkt *pkt, int *is_done)
 	if (usbhs_pipe_is_busy(pipe))
 		return 0;

+	if (usbhs_pipe_is_running(pipe))
+		return 0;
+
 	/*
 	 * pipe enable to prepare packet receive
 	 */
@@ -597,6 +610,7 @@ static int usbhsf_prepare_pop(struct usbhs_pkt *pkt, int *is_done)

 	usbhs_pipe_set_trans_count_if_bulk(pipe, pkt->length);
 	usbhs_pipe_enable(pipe);
+	usbhs_pipe_running(pipe, 1);
 	usbhsf_rx_irq_ctrl(pipe, 1);

 	return 0;
@@ -642,6 +656,7 @@ static int usbhsf_pio_try_pop(struct usbhs_pkt *pkt, int *is_done)
 	    (total_len < maxp)) {		/* short packet */
 		*is_done = 1;
 		usbhsf_rx_irq_ctrl(pipe, 0);
+		usbhs_pipe_running(pipe, 0);
 		usbhs_pipe_disable(pipe);	/* disable pipe first */
 	}

@@ -805,6 +820,7 @@ static void xfer_work(struct work_struct *work)
 	dev_dbg(dev, "  %s %d (%d/ %d)\n",
 		fifo->name, usbhs_pipe_number(pipe), pkt->length, pkt->zero);

+	usbhs_pipe_running(pipe, 1);
 	usbhs_pipe_set_trans_count_if_bulk(pipe, pkt->trans);
 	usbhs_pipe_enable(pipe);
 	usbhsf_dma_start(pipe, fifo);
@@ -836,6 +852,10 @@ static int usbhsf_dma_prepare_push(struct usbhs_pkt *pkt, int *is_done)
 	if ((uintptr_t)(pkt->buf + pkt->actual) & 0x7) /* 8byte alignment */
 		goto usbhsf_pio_prepare_push;

+	/* return at this time if the pipe is running */
+	if (usbhs_pipe_is_running(pipe))
+		return 0;
+
 	/* get enable DMA fifo */
 	fifo = usbhsf_get_dma_fifo(priv, pkt);
 	if (!fifo)
@@ -873,6 +893,7 @@ static int usbhsf_dma_push_done(struct usbhs_pkt *pkt, int *is_done)
 	pkt->actual = pkt->trans;

 	*is_done = !pkt->zero;	/* send zero packet ? */
+	usbhs_pipe_running(pipe, !*is_done);

 	usbhsf_dma_stop(pipe, pipe->fifo);
 	usbhsf_dma_unmap(pkt);
@@ -972,8 +993,10 @@ static int usbhsf_dma_pop_done(struct usbhs_pkt *pkt, int *is_done)
 	if ((pkt->actual = pkt->length) ||	/* receive all data */
 	    (pkt->trans < maxp)) {		/* short packet */
 		*is_done = 1;
+		usbhs_pipe_running(pipe, 0);
 	} else {
 		/* re-enable */
+		usbhs_pipe_running(pipe, 0);
 		usbhsf_prepare_pop(pkt, is_done);
 	}

diff --git a/drivers/usb/renesas_usbhs/pipe.c b/drivers/usb/renesas_usbhs/pipe.c
index 75fbcf6..040bcef 100644
--- a/drivers/usb/renesas_usbhs/pipe.c
+++ b/drivers/usb/renesas_usbhs/pipe.c
@@ -578,6 +578,19 @@ int usbhs_pipe_is_dir_host(struct usbhs_pipe *pipe)
 	return usbhsp_flags_has(pipe, IS_DIR_HOST);
 }

+int usbhs_pipe_is_running(struct usbhs_pipe *pipe)
+{
+	return usbhsp_flags_has(pipe, IS_RUNNING);
+}
+
+void usbhs_pipe_running(struct usbhs_pipe *pipe, int running)
+{
+	if (running)
+		usbhsp_flags_set(pipe, IS_RUNNING);
+	else
+		usbhsp_flags_clr(pipe, IS_RUNNING);
+}
+
 void usbhs_pipe_data_sequence(struct usbhs_pipe *pipe, int sequence)
 {
 	u16 mask = (SQCLR | SQSET);
diff --git a/drivers/usb/renesas_usbhs/pipe.h b/drivers/usb/renesas_usbhs/pipe.h
index 406f36d..d24a059 100644
--- a/drivers/usb/renesas_usbhs/pipe.h
+++ b/drivers/usb/renesas_usbhs/pipe.h
@@ -36,6 +36,7 @@ struct usbhs_pipe {
 #define USBHS_PIPE_FLAGS_IS_USED		(1 << 0)
 #define USBHS_PIPE_FLAGS_IS_DIR_IN		(1 << 1)
 #define USBHS_PIPE_FLAGS_IS_DIR_HOST		(1 << 2)
+#define USBHS_PIPE_FLAGS_IS_RUNNING		(1 << 3)

 	struct usbhs_pkt_handle *handler;

@@ -80,6 +81,9 @@ int usbhs_pipe_probe(struct usbhs_priv *priv);
 void usbhs_pipe_remove(struct usbhs_priv *priv);
 int usbhs_pipe_is_dir_in(struct usbhs_pipe *pipe);
 int usbhs_pipe_is_dir_host(struct usbhs_pipe *pipe);
+int usbhs_pipe_is_running(struct usbhs_pipe *pipe);
+void usbhs_pipe_running(struct usbhs_pipe *pipe, int running);
+
 void usbhs_pipe_init(struct usbhs_priv *priv,
 		     int (*dma_map_ctrl)(struct usbhs_pkt *pkt, int map));
 int usbhs_pipe_get_maxpacket(struct usbhs_pipe *pipe);
-- 
1.7.9.5