Re: [PATCH 4/4] usb: musb: musb_cppi41: Workaround dma stall issue during teardown
From: Sergei Shtylyov <hidden>
Date: 2017-01-09 18:34:10
Also in:
linux-omap
Hello! On 01/09/2017 07:39 PM, Alexandre Bailon wrote:
The dma may hung up if a teardown is initiated while an endpoint is still
The DMA may hang up...
active (Advisory 2.3.27 of da8xx errata). To workaround this issue, add a delay before to initiate the teardown. Signed-off-by: Alexandre Bailon <abailon-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>
[...]
quoted hunk
diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c index 1636385..8fdbc17 100644 --- a/drivers/usb/musb/musb_cppi41.c +++ b/drivers/usb/musb/musb_cppi41.c@@ -547,6 +547,10 @@ static int cppi41_dma_channel_abort(struct dma_channel *channel) } } + /* DA8xx Advisory 2.3.27: wait 250 ms before to start the teardown */ + if (musb->io.quirks & MUSB_DA8XX) + mdelay(250);
This is a horrible workaround, not even msleep()... [...] MBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html