linux-kernel - [PATCH] usb: musb: Disable pullup at init

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Sat, 14 Dec 2019 23:18:15 +0100
From:   Paul Cercueil <paul@...pouillou.net>
To:     Bin Liu <b-liu@...com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     od@...c.me, linux-usb@...r.kernel.org,
        linux-kernel@...r.kernel.org, Paul Cercueil <paul@...pouillou.net>
Subject: [PATCH] usb: musb: Disable pullup at init

The pullup may be already enabled before the driver is initialized. This
happens for instance on JZ4740.

It has to be disabled at init time, as we cannot guarantee that a gadget
driver will be bound to the UDC.

Signed-off-by: Paul Cercueil <paul@...pouillou.net>
Suggested-by: Bin Liu <b-liu@...com>
---
 drivers/usb/musb/musb_core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 15cca912c53e..c91d5c2ed4ad 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -2310,6 +2310,9 @@ musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl)
 	musb_disable_interrupts(musb);
 	musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
 
+	/* MUSB_POWER_SOFTCONN might be already set, JZ4740 does this. */
+	musb_writeb(musb->mregs, MUSB_POWER, 0);
+
 	/* Init IRQ workqueue before request_irq */
 	INIT_DELAYED_WORK(&musb->irq_work, musb_irq_work);
 	INIT_DELAYED_WORK(&musb->deassert_reset_work, musb_deassert_reset);
-- 
2.24.0