[PATCH 1/3 v2] usb: pci-quirks: Add a common mutex for the I/O port pair of SB800

From: Zoltan Boszormenyi
Date: Mon Apr 03 2017 - 03:52:28 EST


This patch adds a common mutex in the USB PCI quirks code and starts
using it to synchronize access to the I/O port pair 0xcd6 / 0xcd7 on
SB800.

These I/O ports are also used by i2c-piix4 and sp5100_tco, the next
two patches port these drivers to use this common mutex.

v2: No extra header and no wrapper for mutex_lock() / mutex_unlock()

Signed-off-by: Zoltan Boszormenyi <zboszor@xxxxx>
---
drivers/usb/host/pci-quirks.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index a9a1e4c..1ef0ada 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -279,6 +279,9 @@ bool usb_amd_prefetch_quirk(void)
}
EXPORT_SYMBOL_GPL(usb_amd_prefetch_quirk);

+DEFINE_MUTEX(sb800_mutex);
+EXPORT_SYMBOL_GPL(sb800_mutex);
+
/*
* The hardware normally enables the A-link power management feature, which
* lets the system lower the power consumption in idle states.
@@ -314,11 +317,13 @@ static void usb_amd_quirk_pll(int disable)
if (amd_chipset.sb_type.gen == AMD_CHIPSET_SB800 ||
amd_chipset.sb_type.gen == AMD_CHIPSET_HUDSON2 ||
amd_chipset.sb_type.gen == AMD_CHIPSET_BOLTON) {
+ mutex_lock(&sb800_mutex);
outb_p(AB_REG_BAR_LOW, 0xcd6);
addr_low = inb_p(0xcd7);
outb_p(AB_REG_BAR_HIGH, 0xcd6);
addr_high = inb_p(0xcd7);
addr = addr_high << 8 | addr_low;
+ mutex_unlock(&sb800_mutex);

outl_p(0x30, AB_INDX(addr));
outl_p(0x40, AB_DATA(addr));
--
2.9.3