[PATCH v2 02/11] usb: xhci: move device slot enabling register write

[Niklas Neronin <niklas.neronin@linux.intel.com>]

Refactor the setting of the Number of Device Slots Enabled field into a
separate function, relocating it to xhci_init().

The xHCI driver consistently sets the number of enabled device slots to the
maximum value. The new function is named to reflect this behavior.

Remove the "// " prefix from trace messages, as it is unnecessary and
distracting.

Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
---
 drivers/usb/host/xhci-mem.c | 15 +--------------
 drivers/usb/host/xhci.c     | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index d309e8e9d508..dbf0187086db 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -2385,23 +2385,10 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
 	struct xhci_interrupter *ir;
 	struct device	*dev = xhci_to_hcd(xhci)->self.sysdev;
 	dma_addr_t	dma;
-	unsigned int	val, val2;
+	unsigned int	val;
 	u64		val_64;
 	u32		temp;
 
-	/*
-	 * Program the Number of Device Slots Enabled field in the CONFIG
-	 * register with the max value of slots the HC can handle.
-	 */
-	val = HCS_MAX_SLOTS(readl(&xhci->cap_regs->hcs_params1));
-	xhci_dbg_trace(xhci, trace_xhci_dbg_init,
-			"// xHC can handle at most %d device slots.", val);
-	val2 = readl(&xhci->op_regs->config_reg);
-	val |= (val2 & ~HCS_SLOTS_MASK);
-	xhci_dbg_trace(xhci, trace_xhci_dbg_init,
-			"// Setting Max device slots reg = 0x%x.", val);
-	writel(val, &xhci->op_regs->config_reg);
-
 	/*
 	 * xHCI section 5.4.6 - Device Context array must be
 	 * "physically contiguous and 64-byte (cache line) aligned".
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index ec2e4a2d8af0..4de51ba851d8 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -477,6 +477,24 @@ static void xhci_hcd_page_size(struct xhci_hcd *xhci)
 		       xhci->page_size >> 10);
 }
 
+static void xhci_enable_max_dev_slots(struct xhci_hcd *xhci)
+{
+	u32 config_reg;
+	u32 max_slots;
+
+	max_slots = HCS_MAX_SLOTS(xhci->hcs_params1);
+	xhci_dbg_trace(xhci, trace_xhci_dbg_init, "xHC can handle at most %d device slots",
+		       max_slots);
+
+	config_reg = readl(&xhci->op_regs->config_reg);
+	config_reg &= ~HCS_SLOTS_MASK;
+	config_reg |= max_slots;
+
+	xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Setting Max device slots reg = 0x%x",
+		       config_reg);
+	writel(config_reg, &xhci->op_regs->config_reg);
+}
+
 /*
  * Initialize memory for HCD and xHC (one-time init).
  *
@@ -502,6 +520,9 @@ static int xhci_init(struct usb_hcd *hcd)
 	if (retval)
 		return retval;
 
+	/* Set the Number of Device Slots Enabled to the maximum supported value */
+	xhci_enable_max_dev_slots(xhci);
+
 	/* Initializing Compliance Mode Recovery Data If Needed */
 	if (xhci_compliance_mode_recovery_timer_quirk_check()) {
 		xhci->quirks |= XHCI_COMP_MODE_QUIRK;
-- 
2.47.2