[PATCH v2] usb: musb: musb_dsps: Wait for controller reset

[PATCH v2] usb: musb: musb_dsps: Wait for controller reset

[Ettore Chimenti]

From: Andrew Goodbody <andrew.goodbody@linaro.org>

After soft resetting the USB controller wait for it to complete and then
set the mode of the controller. This ensures that the controller is in a
sane state. The timeout value used is just large as the board is likely
broken if it is ever reached so no need to optimise. It was tested with
a timeout of 500us which worked so gave it a 10x safety margin and used
5000us as the timeout value. If the reset times out let it cleanup on
error path exit to prevent leaks.

Fixes: 9ecb887522a0 ("usb: musb: Add support for ti81xx platform")
Signed-off-by: Andrew Goodbody <andrew.goodbody@linaro.org>
Signed-off-by: Ettore Chimenti <ettore.chimenti@linaro.org>
---
Changes in v2:
- Added cleanup on error path (Sashiko)
- Link to v1: https://patch.msgid.link/20261014-patch-ektor5-dm8168-usb-v1-1-9670414271d6@linaro.org

To: Bin Liu <b-liu@ti.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Felipe Balbi <balbi@ti.com>
To: Ajay Kumar Gupta <ajay.gupta@ti.com>
To: Ravi Babu <ravibabu@ti.com>
Cc: linux-usb@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/usb/musb/musb_dsps.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c
index efd1f0dbb926..91958b7000d7 100644
--- a/drivers/usb/musb/musb_dsps.c
+++ b/drivers/usb/musb/musb_dsps.c
@@ -15,6 +15,7 @@
  */
 
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/irq.h>
 #include <linux/err.h>
 #include <linux/platform_device.h>
@@ -35,6 +36,7 @@
 #include "musb_core.h"
 
 static const struct of_device_id musb_dsps_of_match[];
+static int dsps_musb_set_mode(struct musb *musb, u8 mode);
 
 /*
  * DSPS musb wrapper register offset.
@@ -466,7 +468,16 @@ static int dsps_musb_init(struct musb *musb)
 	timer_setup(&musb->dev_timer, otg_timer, 0);
 
 	/* Reset the musb */
-	musb_writel(reg_base, wrp->control, (1 << wrp->reset));
+	musb_writel(reg_base, wrp->control, BIT(wrp->reset));
+	read_poll_timeout(musb_readl, val, !(val & BIT(wrp->reset)), 2, 5000,
+			  false, reg_base, wrp->control);
+	if (val & BIT(wrp->reset)) {
+		phy_power_off(musb->phy);
+		phy_exit(musb->phy);
+		return -ENODEV;
+	}
+
+	dsps_musb_set_mode(musb, musb->port_mode);
 
 	musb->isr = dsps_interrupt;
 

---
base-commit: d135ab453a7400a34930bdda1ef4bdc8acfac80e
change-id: 20261014-patch-ektor5-dm8168-usb-d6ca2a5189f6

Best regards,
--  
Ettore Chimenti <ettore.chimenti@linaro.org>

Re: [PATCH v2] usb: musb: musb_dsps: Wait for controller reset

[sashiko-bot]

> From: Andrew Goodbody <andrew.goodbody@linaro.org>
> 
> After soft resetting the USB controller wait for it to complete and then
> set the mode of the controller. This ensures that the controller is in a
> sane state. The timeout value used is just large as the board is likely
> broken if it is ever reached so no need to optimise. It was tested with
> a timeout of 500us which worked so gave it a 10x safety margin and used
> 5000us as the timeout value. If the reset times out let it cleanup on
> error path exit to prevent leaks.
> 
> Fixes: 9ecb887522a0 ("usb: musb: Add support for ti81xx platform")
> Signed-off-by: Andrew Goodbody <andrew.goodbody@linaro.org>
> Signed-off-by: Ettore Chimenti <ettore.chimenti@linaro.org>

Sashiko has reviewed this patch and found no issues.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261028-patch-ektor5-dm8168-usb-v2-1-c2af306eb228@linaro.org?part=1