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authorFelipe Balbi <balbi@ti.com>2013-12-30 12:33:53 -0600
committerFelipe Balbi <balbi@ti.com>2015-03-09 10:38:48 -0500
commite3c93e1a3f35be4cf1493d3ccfb0c6d9209e4922 (patch)
treec75b4cfcfd7bff9f14189e1932959ab655f8ca3e /drivers/usb/musb
parentd5638fcf15bc65584877f00d4b0094cc4a66ad4e (diff)
downloadblackbird-op-linux-e3c93e1a3f35be4cf1493d3ccfb0c6d9209e4922.tar.gz
blackbird-op-linux-e3c93e1a3f35be4cf1493d3ccfb0c6d9209e4922.zip
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@vger.kernel.org> Signed-off-by: Felipe Balbi <balbi@ti.com>
Diffstat (limited to 'drivers/usb/musb')
-rw-r--r--drivers/usb/musb/musb_core.c44
1 files 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++;
}
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