From 8b3e233e8121d241a93f27a093c1440673d3a7ff Mon Sep 17 00:00:00 2001 From: Dinh Nguyen Date: Wed, 7 May 2014 08:30:33 -0500 Subject: [PATCH] usb: dwc2: Disable descriptor dma mode by default Even though the IP supports Descriptor DMA mode, it does not support SPLIT transactions in this mode. So the driver, in its currently form, will not support LS/FS devices when connected to a HS Hub if Descriptor DMA mode is enabled. So we should just default to disable descriptor dma mode. Signed-off-by: Dinh Nguyen Acked-by: Paul Zimmerman Signed-off-by: Greg Kroah-Hartman --- drivers/usb/dwc2/platform.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c index eaba547..a10e7a3 100644 --- a/drivers/usb/dwc2/platform.c +++ b/drivers/usb/dwc2/platform.c @@ -134,6 +134,12 @@ static int dwc2_driver_probe(struct platform_device *dev) /* Default all params to autodetect */ dwc2_set_all_params(&defparams, -1); params = &defparams; + + /* + * Disable descriptor dma mode by default as the HW can support + * it, but does not support it for SPLIT transactions. + */ + defparams.dma_desc_enable = 0; } hsotg = devm_kzalloc(&dev->dev, sizeof(*hsotg), GFP_KERNEL); -- 2.7.4