USB host: Move AMD PLL quirk to pci-quirks.c

This patch moves the AMD PLL quirk code in OHCI/EHCI driver to pci-quirks.c,
and exports the functions to be used by xHCI driver later.

AMD PLL quirk disable the optional PM feature inside specific
SB700/SB800/Hudson-2/3 platforms under the following conditions:

1. If an isochronous device is connected to OHCI/EHCI/xHCI port and is active;
2. Optional PM feature that powers down the internal Bus PLL when the link is
   in low power state is enabled.

Without AMD PLL quirk, USB isochronous stream may stutter or have breaks
occasionally, which greatly impair the performance of audio/video streams.

Currently AMD PLL quirk is implemented in OHCI and EHCI driver, and will be
added to xHCI driver too. They are doing similar things actually, so move
the quirk code to pci-quirks.c, which has several advantages:

1. Remove duplicate defines and functions in OHCI/EHCI (and xHCI) driver and
   make them cleaner;
2. AMD chipset information will be probed only once and then stored.
   Currently they're probed during every OHCI/EHCI initialization, move
   the detect code to pci-quirks.c saves the repeat detect cost;
3. Build up synchronization among OHCI/EHCI/xHCI driver. In current
   code, every host controller enable/disable PLL only according to
   its own status, and may enable PLL while there is still isoc transfer on
   other HCs. Move the quirk to pci-quirks.c prevents this issue.

Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alex He <alex.he@amd.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2 insertions, 11 deletions

diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index 759a12ff8048..7b791bf1e7b4 100644
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -75,6 +75,7 @@ static const char	hcd_name [] = "ohci_hcd";
 #define STATECHANGE_DELAY       msecs_to_jiffies(300)
 
 #include "ohci.h"
+#include "pci-quirks.h"
 
 static void ohci_dump (struct ohci_hcd *ohci, int verbose);
 static int ohci_init (struct ohci_hcd *ohci);
@@ -85,18 +86,8 @@ static int ohci_restart (struct ohci_hcd *ohci);
 #endif
 
 #ifdef CONFIG_PCI
-static void quirk_amd_pll(int state);
-static void amd_iso_dev_put(void);
 static void sb800_prefetch(struct ohci_hcd *ohci, int on);
 #else
-static inline void quirk_amd_pll(int state)
-{
-        return;
-}
-static inline void amd_iso_dev_put(void)
-{
-        return;
-}
 static inline void sb800_prefetch(struct ohci_hcd *ohci, int on)
 {
         return;
@@ -912,7 +903,7 @@ static void ohci_stop (struct usb_hcd *hcd)
         if (quirk_zfmicro(ohci))
                 del_timer(&ohci->unlink_watchdog);
         if (quirk_amdiso(ohci))
-                amd_iso_dev_put();
+                usb_amd_dev_put();
 
         remove_debug_files (ohci);
         ohci_mem_cleanup (ohci);