Commit 6596a926 authored Feb 24, 2015 by Mathias Nyman Committed by Greg Kroah-Hartman Feb 24, 2015

xhci: Allocate correct amount of scratchpad buffers



Include the high order bit fields for Max scratchpad buffers when
calculating how many scratchpad buffers are needed.

I'm suprised this hasn't caused more issues, we never allocated more than
32 buffers even if xhci needed more. Either we got lucky and xhci never
really used past that area, or then we got enough zeroed dma memory anyway.

Should be backported as far back as possible

Reported-by: Tim Chen <tim.c.chen@linux.intel.com>
Tested-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 1e7e4fb6

drivers/usb/host/xhci.h

+3 −2

Original line number	Diff line number	Diff line
		@@ -88,9 +88,10 @@ struct xhci_cap_regs {
		#define HCS_IST(p) (((p) >> 0) & 0xf)
		/* bits 4:7, max number of Event Ring segments */
		#define HCS_ERST_MAX(p) (((p) >> 4) & 0xf)
		/* bits 21:25 Hi 5 bits of Scratchpad buffers SW must allocate for the HW */
		/* bit 26 Scratchpad restore - for save/restore HW state - not used yet */
		/* bits 27:31 number of Scratchpad buffers SW must allocate for the HW */
		#define HCS_MAX_SCRATCHPAD(p) (((p) >> 27) & 0x1f)
		/* bits 27:31 Lo 5 bits of Scratchpad buffers SW must allocate for the HW */
		#define HCS_MAX_SCRATCHPAD(p) ((((p) >> 16) & 0x3e0) \| (((p) >> 27) & 0x1f))

		/* HCSPARAMS3 - hcs_params3 - bitmasks */
		/* bits 0:7, Max U1 to U0 latency for the roothub ports */

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