This is a note to let you know that I've just added the patch titled
usb: musb: core: fix TX/RX endpoint order
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From e3c93e1a3f35be4cf1493d3ccfb0c6d9209e4922 Mon Sep 17 00:00:00 2001
From: Felipe Balbi <balbi@xxxxxx>
Date: Mon, 30 Dec 2013 12:33:53 -0600
Subject: usb: musb: core: fix TX/RX endpoint order
As per Mentor Graphics' documentation, we should
always handle TX endpoints before RX endpoints.
This patch fixes that error while also updating
some hard-to-read comments which were scattered
around musb_interrupt().
This patch should be backported as far back as
possible since this error has been in the driver
since it's conception.
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
drivers/usb/musb/musb_core.c | 44 ++++++++++++++++++++++++++------------------
1 file changed, 26 insertions(+), 18 deletions(-)
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 067920f2d570..461bfe8efcf2 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -1597,16 +1597,30 @@ irqreturn_t musb_interrupt(struct musb *musb)
is_host_active(musb) ? "host" : "peripheral",
musb->int_usb, musb->int_tx, musb->int_rx);
- /* the core can interrupt us for multiple reasons; docs have
- * a generic interrupt flowchart to follow
+ /**
+ * According to Mentor Graphics' documentation, flowchart on page 98,
+ * IRQ should be handled as follows:
+ *
+ * . Resume IRQ
+ * . Session Request IRQ
+ * . VBUS Error IRQ
+ * . Suspend IRQ
+ * . Connect IRQ
+ * . Disconnect IRQ
+ * . Reset/Babble IRQ
+ * . SOF IRQ (we're not using this one)
+ * . Endpoint 0 IRQ
+ * . TX Endpoints
+ * . RX Endpoints
+ *
+ * We will be following that flowchart in order to avoid any problems
+ * that might arise with internal Finite State Machine.
*/
+
if (musb->int_usb)
retval |= musb_stage0_irq(musb, musb->int_usb,
devctl);
- /* "stage 1" is handling endpoint irqs */
-
- /* handle endpoint 0 first */
if (musb->int_tx & 1) {
if (is_host_active(musb))
retval |= musb_h_ep0_irq(musb);
@@ -1614,37 +1628,31 @@ irqreturn_t musb_interrupt(struct musb *musb)
retval |= musb_g_ep0_irq(musb);
}
- /* RX on endpoints 1-15 */
- reg = musb->int_rx >> 1;
+ reg = musb->int_tx >> 1;
ep_num = 1;
while (reg) {
if (reg & 1) {
- /* musb_ep_select(musb->mregs, ep_num); */
- /* REVISIT just retval = ep->rx_irq(...) */
retval = IRQ_HANDLED;
if (is_host_active(musb))
- musb_host_rx(musb, ep_num);
+ musb_host_tx(musb, ep_num);
else
- musb_g_rx(musb, ep_num);
+ musb_g_tx(musb, ep_num);
}
-
reg >>= 1;
ep_num++;
}
- /* TX on endpoints 1-15 */
- reg = musb->int_tx >> 1;
+ reg = musb->int_rx >> 1;
ep_num = 1;
while (reg) {
if (reg & 1) {
- /* musb_ep_select(musb->mregs, ep_num); */
- /* REVISIT just retval |= ep->tx_irq(...) */
retval = IRQ_HANDLED;
if (is_host_active(musb))
- musb_host_tx(musb, ep_num);
+ musb_host_rx(musb, ep_num);
else
- musb_g_tx(musb, ep_num);
+ musb_g_rx(musb, ep_num);
}
+
reg >>= 1;
ep_num++;
}
--
2.3.4
--
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