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From:   Neil Armstrong <narmstrong@baylibre.com>
To:     balbi@kernel.org
Cc:     linux-usb@vger.kernel.org, linux-amlogic@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Neil Armstrong <narmstrong@baylibre.com>
Subject: [PATCH] usb: dwc3-meson-g12a: fix usb2 PHY glue init when phy0 is disabled
Date:   Tue,  1 Jun 2021 10:48:30 +0200
Message-Id: <20210601084830.260196-1-narmstrong@baylibre.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

When only PHY1 is used (for example on Odroid-HC4), the regmap init code
uses the usb2 ports when doesn't initialize the PHY1 regmap entry.

This fixes:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
...
pc : regmap_update_bits_base+0x40/0xa0
lr : dwc3_meson_g12a_usb2_init_phy+0x4c/0xf8
...
Call trace:
regmap_update_bits_base+0x40/0xa0
dwc3_meson_g12a_usb2_init_phy+0x4c/0xf8
dwc3_meson_g12a_usb2_init+0x7c/0xc8
dwc3_meson_g12a_usb_init+0x28/0x48
dwc3_meson_g12a_probe+0x298/0x540
platform_probe+0x70/0xe0
really_probe+0xf0/0x4d8
driver_probe_device+0xfc/0x168
...

Fixes: 013af227f58a97 ("usb: dwc3: meson-g12a: handle the phy and glue registers separately")
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/usb/dwc3/dwc3-meson-g12a.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/dwc3-meson-g12a.c b/drivers/usb/dwc3/dwc3-meson-g12a.c
index bdf1f98dfad8..9c944bc6d555 100644
--- a/drivers/usb/dwc3/dwc3-meson-g12a.c
+++ b/drivers/usb/dwc3/dwc3-meson-g12a.c
@@ -651,7 +651,7 @@ static int dwc3_meson_g12a_setup_regmaps(struct dwc3_meson_g12a *priv,
 		return PTR_ERR(priv->usb_glue_regmap);
 
 	/* Create a regmap for each USB2 PHY control register set */
-	for (i = 0; i < priv->usb2_ports; i++) {
+	for (i = 0; i < priv->drvdata->num_phys; i++) {
 		struct regmap_config u2p_regmap_config = {
 			.reg_bits = 8,
 			.val_bits = 32,
@@ -659,6 +659,9 @@ static int dwc3_meson_g12a_setup_regmaps(struct dwc3_meson_g12a *priv,
 			.max_register = U2P_R1,
 		};
 
+		if (!strstr(priv->drvdata->phy_names[i], "usb2"))
+			continue;
+
 		u2p_regmap_config.name = devm_kasprintf(priv->dev, GFP_KERNEL,
 							"u2p-%d", i);
 		if (!u2p_regmap_config.name)
-- 
2.25.1