Thread (3 messages) flat view 3 messages, 3 authors, 2015-03-04

Re: [PATCH 07/10] usb: Make sure that DWC2 initializes after the power channel mailbox driver.

From: Lee Jones <hidden>
Date: 2015-03-03 08:32:50

Possibly related (same subject, not in this thread)

On Mon, 02 Mar 2015, Eric Anholt wrote:
quoted hunk
This gets USB working on the Raspberry Pi without relying on U-Boot to
send the power message for us.  Without it, you would get warnings
about fifo sizes and "dwc2_core_reset() HANG! Soft Reset
GRSTCTL=80000001" leading to a failed probe.

Signed-off-by: Eric Anholt <redacted>
Cc: John Youn <johnyoun-HKixBCOQz3hWk0Htik3J/w@public.gmane.org>
---
 drivers/mailbox/bcm2835-mailbox-power.c |  5 +++++
 drivers/usb/dwc2/platform.c             | 20 ++++++++++++++++++++
 2 files changed, 25 insertions(+)
diff --git a/drivers/mailbox/bcm2835-mailbox-power.c b/drivers/mailbox/bcm2835-mailbox-power.c
index f09c855..d0faca2 100644
--- a/drivers/mailbox/bcm2835-mailbox-power.c
+++ b/drivers/mailbox/bcm2835-mailbox-power.c
@@ -31,6 +31,9 @@ struct bcm_mbox_power {
 	uint32_t response;
 };
 
+bool bcm2835_mbox_power_initialized;
+EXPORT_SYMBOL_GPL(bcm2835_mbox_power_initialized);
This is pretty ugly.  What is it used for?  Is there any way you can
use an API for it instead?
quoted hunk
 struct bcm_mbox_power *mbox_power;
 
 static void response_callback(struct mbox_client *cl, void *mssg)
@@ -92,6 +95,7 @@ static int bcm2835_mbox_power_probe(struct platform_device *pdev)
 		bcm_mbox_set_power(BCM_POWER_USB);
 		bcm2835_mbox_power_initialized = true;
 	}
+	bcm2835_mbox_power_initialized = true;
 
 	return ret;
 }
@@ -99,6 +103,7 @@ static int bcm2835_mbox_power_probe(struct platform_device *pdev)
 static int bcm2835_mbox_power_remove(struct platform_device *pdev)
 {
 	bcm_mbox_set_power(0);
+	bcm2835_mbox_power_initialized = false;
 
 	mbox_free_channel(mbox_power->chan);
 
diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index ae095f0..2a4a3a6 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -136,6 +136,20 @@ static const struct of_device_id dwc2_of_match_table[] = {
 };
 MODULE_DEVICE_TABLE(of, dwc2_of_match_table);
 
+extern bool bcm2835_mbox_power_initialized;
Ughhh, *shudder*.
+bool bcm2835_usb_power_enabled(void)
+{
+#ifdef CONFIG_BCM2835_MBOX
Please don't put #ifdeffery in *.c files.  If you have to match on
CONFIG_* options, please do so using inlines in a header file
somewhere.
quoted hunk
+	return bcm2835_mbox_power_initialized;
+#else
+	/* Assume that somebody else has enabled the power for us
+	 * (like U-Boot).
+	 */
+	return true;
+#endif
+}
+
 /**
  * dwc2_driver_probe() - Called when the DWC_otg core is bound to the DWC_otg
  * driver
@@ -175,6 +189,12 @@ static int dwc2_driver_probe(struct platform_device *dev)
 		defparams.dma_desc_enable = 0;
 	}
 
+	/* Make sure the platform driver for enabling the power has
+	 * initialized before we do.
+	 */
This multi-line comment is unconventional.

See: Documentation/CodingStyle
+	if (params == &params_bcm2835 && !bcm2835_usb_power_enabled())
+		return -EPROBE_DEFER;
Why don't you cut out the middle man and get rid of all of these awful
exports?

include/linux/platform/bcm2835.h

#ifdef CONFIG_BCM2835_MBOX
static inline bool bcm2835_is_usb_powered()
{
	return bcm2835_mbox_is_usb_powered();
}
#else
static inline bool bcm2835_is_usb_powered()
{
	/* 
	 * If BCM2835 isn't using its Mailbox(es), the
	 * bootloader is charged with powering up USB.
	 */
	return true;
}
#endif 
 	hsotg = devm_kzalloc(&dev->dev, sizeof(*hsotg), GFP_KERNEL);
 	if (!hsotg)
 		return -ENOMEM;
--
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