[PATCH v2 03/10] xhci: dbc: Use sysfs_emit() to instead of scnprintf()

[Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>]

Follow the advice of the Documentation/filesystems/sysfs.rst and show()
should only use sysfs_emit() or sysfs_emit_at() when formatting the
value to be returned to user space.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
 drivers/usb/host/xhci-dbgcap.c | 44 +++++++++++++---------------------
 drivers/usb/host/xhci-dbgcap.h |  1 +
 2 files changed, 17 insertions(+), 28 deletions(-)

diff --git a/drivers/usb/host/xhci-dbgcap.c b/drivers/usb/host/xhci-dbgcap.c
index f505b79afe53..df14e336370d 100644
--- a/drivers/usb/host/xhci-dbgcap.c
+++ b/drivers/usb/host/xhci-dbgcap.c
@@ -910,41 +910,29 @@ static void xhci_dbc_handle_events(struct work_struct *work)
 	mod_delayed_work(system_wq, &dbc->event_work, 1);
 }
 
+static const char * const dbc_state_strings[DS_MAX] = {
+	[DS_DISABLED] = "disabled",
+	[DS_INITIALIZED] = "initialized",
+	[DS_ENABLED] = "enabled",
+	[DS_CONNECTED] = "connected",
+	[DS_CONFIGURED] = "configured",
+	[DS_STALLED] = "stalled",
+};
+
 static ssize_t dbc_show(struct device *dev,
 			struct device_attribute *attr,
 			char *buf)
 {
-	const char		*p;
 	struct xhci_dbc		*dbc;
 	struct xhci_hcd		*xhci;
 
 	xhci = hcd_to_xhci(dev_get_drvdata(dev));
 	dbc = xhci->dbc;
 
-	switch (dbc->state) {
-	case DS_DISABLED:
-		p = "disabled";
-		break;
-	case DS_INITIALIZED:
-		p = "initialized";
-		break;
-	case DS_ENABLED:
-		p = "enabled";
-		break;
-	case DS_CONNECTED:
-		p = "connected";
-		break;
-	case DS_CONFIGURED:
-		p = "configured";
-		break;
-	case DS_STALLED:
-		p = "stalled";
-		break;
-	default:
-		p = "unknown";
-	}
+	if (dbc->state >= ARRAY_SIZE(dbc_state_strings))
+		return sysfs_emit(buf, "unknown\n");
 
-	return sprintf(buf, "%s\n", p);
+	return sysfs_emit(buf, "%s\n", dbc_state_strings[dbc->state]);
 }
 
 static ssize_t dbc_store(struct device *dev,
@@ -977,7 +965,7 @@ static ssize_t dbc_idVendor_show(struct device *dev,
 	xhci = hcd_to_xhci(dev_get_drvdata(dev));
 	dbc = xhci->dbc;
 
-	return sprintf(buf, "%04x\n", dbc->idVendor);
+	return sysfs_emit(buf, "%04x\n", dbc->idVendor);
 }
 
 static ssize_t dbc_idVendor_store(struct device *dev,
@@ -1017,7 +1005,7 @@ static ssize_t dbc_idProduct_show(struct device *dev,
 	xhci = hcd_to_xhci(dev_get_drvdata(dev));
 	dbc = xhci->dbc;
 
-	return sprintf(buf, "%04x\n", dbc->idProduct);
+	return sysfs_emit(buf, "%04x\n", dbc->idProduct);
 }
 
 static ssize_t dbc_idProduct_store(struct device *dev,
@@ -1056,7 +1044,7 @@ static ssize_t dbc_bcdDevice_show(struct device *dev,
 	xhci = hcd_to_xhci(dev_get_drvdata(dev));
 	dbc = xhci->dbc;
 
-	return sprintf(buf, "%04x\n", dbc->bcdDevice);
+	return sysfs_emit(buf, "%04x\n", dbc->bcdDevice);
 }
 
 static ssize_t dbc_bcdDevice_store(struct device *dev,
@@ -1096,7 +1084,7 @@ static ssize_t dbc_bInterfaceProtocol_show(struct device *dev,
 	xhci = hcd_to_xhci(dev_get_drvdata(dev));
 	dbc = xhci->dbc;
 
-	return sprintf(buf, "%02x\n", dbc->bInterfaceProtocol);
+	return sysfs_emit(buf, "%02x\n", dbc->bInterfaceProtocol);
 }
 
 static ssize_t dbc_bInterfaceProtocol_store(struct device *dev,
diff --git a/drivers/usb/host/xhci-dbgcap.h b/drivers/usb/host/xhci-dbgcap.h
index 51a7ab3ba0ca..e39e3ae1677a 100644
--- a/drivers/usb/host/xhci-dbgcap.h
+++ b/drivers/usb/host/xhci-dbgcap.h
@@ -82,6 +82,7 @@ enum dbc_state {
 	DS_CONNECTED,
 	DS_CONFIGURED,
 	DS_STALLED,
+	DS_MAX
 };
 
 struct dbc_ep {
-- 
2.40.0.1.gaa8946217a0b