From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexandre Bailon Subject: [RESEND PATCH v6 3/4] usb: musb: musb_cppi41: Workaround DMA stall issue during teardown Date: Fri, 24 Mar 2017 15:35:59 +0100 Message-ID: <20170324143600.4704-4-abailon@baylibre.com> References: <20170324143600.4704-1-abailon@baylibre.com> Return-path: In-Reply-To: <20170324143600.4704-1-abailon-rdvid1DuHRBWk0Htik3J/w@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: b-liu-l0cyMroinI0@public.gmane.org Cc: linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, ptitiano-rdvid1DuHRBWk0Htik3J/w@public.gmane.org, khilman-rdvid1DuHRBWk0Htik3J/w@public.gmane.org, nsekhar-l0cyMroinI0@public.gmane.org, tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org, sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org, linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Alexandre Bailon List-Id: linux-omap@vger.kernel.org The DMA may hang up if a teardown is initiated while an endpoint is still 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 --- drivers/usb/musb/da8xx.c | 2 +- drivers/usb/musb/musb_core.h | 1 + drivers/usb/musb/musb_cppi41.c | 4 ++++ 3 files changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/usb/musb/da8xx.c b/drivers/usb/musb/da8xx.c index 458a499..ed28afd 100644 --- a/drivers/usb/musb/da8xx.c +++ b/drivers/usb/musb/da8xx.c @@ -483,7 +483,7 @@ da8xx_dma_controller_create(struct musb *musb, void __iomem *base) static const struct musb_platform_ops da8xx_ops = { .quirks = MUSB_INDEXED_EP | MUSB_PRESERVE_SESSION | - MUSB_DMA_CPPI41, + MUSB_DMA_CPPI41 | MUSB_DA8XX, .init = da8xx_musb_init, .exit = da8xx_musb_exit, diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h index 5b708be..3e98d42 100644 --- a/drivers/usb/musb/musb_core.h +++ b/drivers/usb/musb/musb_core.h @@ -172,6 +172,7 @@ struct musb_io; */ struct musb_platform_ops { +#define MUSB_DA8XX BIT(8) #define MUSB_PRESERVE_SESSION BIT(7) #define MUSB_DMA_UX500 BIT(6) #define MUSB_DMA_CPPI41 BIT(5) diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c index 355655f..e7c8b1b 100644 --- a/drivers/usb/musb/musb_cppi41.c +++ b/drivers/usb/musb/musb_cppi41.c @@ -571,6 +571,10 @@ 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); + tdbit = 1 << cppi41_channel->port_num; if (is_tx) tdbit <<= 16; -- 2.10.2 -- 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