USB: EHCI: tegra: set txfill_tuning
authorStephen Warren <swarren@nvidia.com>
Mon, 14 Apr 2014 21:21:23 +0000 (15:21 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 16 Apr 2014 20:59:13 +0000 (13:59 -0700)
commit4f2fe2d27472f4a5dbd875888af4fc5175f3fdc5
treebf93520a69ccb388c052924bde8667cbbf3ddfff
parente155b5b8d2d42455d3a94c2460c287e97184ec61
USB: EHCI: tegra: set txfill_tuning

To avoid memory fetch underflows with larger USB transfers, Tegra SoCs
need txfill_tuning's txfifothresh register field set to a non-default
value. Add a custom reset override in order to set this up.

These values are recommended practice for all Tegra chips. However,
I've only noticed practical problems when not setting them this way on
systems using Tegra124. Hence, CC: stable only for recent kernels which
actually support Tegra124.

Cc: <stable@vger.kernel.org> # 3.14+
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/host/ehci-tegra.c