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FAILED: patch "[PATCH] usb: gadget: musb: fix short isoc packets with inventra dma" failed to apply to 4.4-stable tree

PATCH [email protected] 1 participant 1 message Feb 11, 2019

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Stable branch USB MUSB multipoint high speed dual-role controller
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The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From c418fd6c01fbc5516a2cd1eaf1df1ec86869028a Mon Sep 17 00:00:00 2001
From: Paul Elder <[email protected]>
Date: Wed, 30 Jan 2019 08:13:21 -0600
Subject: [PATCH] usb: gadget: musb: fix short isoc packets with inventra dma

Handling short packets (length < max packet size) in the Inventra DMA engine in the MUSB driver causes the MUSB DMA controller to hang. An example of a problem that is caused by this problem is when streaming video out of a UVC gadget, only the first video frame is transferred.

For short packets (mode-0 or mode-1 DMA), MUSB_TXCSR_TXPKTRDY must be set manually by the driver. This was previously done in musb_g_tx (musb_gadget.c), but incorrectly (all csr flags were cleared, and only MUSB_TXCSR_MODE and MUSB_TXCSR_TXPKTRDY were set). Fixing that problem allows some requests to be transferred correctly, but multiple requests were often put together in one USB packet, and caused problems if the packet size was not a multiple of 4. Instead, set MUSB_TXCSR_TXPKTRDY in dma_controller_irq (musbhsdma.c), just like host mode transfers.

This topic was originally tackled by Nicolas Boichat [0] [1] and is discussed further at [2] as part of his GSoC project [3].

[0] https://groups.google.com/forum/?hl=en#!topic/beagleboard-gsoc/k8Azwfp75CU
[1] https://gitorious.org/beagleboard-usbsniffer/beagleboard-usbsniffer-kernel/commit/b0be3b6cc195ba732189b04f1d43ec843c3e54c9?p=beagleboard-usbsniffer:beagleboard-usbsniffer-kernel.git;a=patch;h=b0be3b6cc195ba732189b04f1d43ec843c3e54c9
[2] http://beagleboard-usbsniffer.blogspot.com/2010/07/musb-isochronous-transfers-fixed.html
[3] http://elinux.org/BeagleBoard/GSoC/USBSniffer

Fixes 550a7375fe72 ("USB: Add MUSB and TUSB support")
Signed-off-by Paul Elder <[email protected]>
Signed-off-by Bin Liu <[email protected]>
Cc stable <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
drivers/usb/musb/musb_gadget.c +1 -12
index eae8b1b1b45b..ffe462a657b1 100644
@@ -452,13 +452,10 @@ void musb_g_tx(struct musb *musb, u8 epnum)
 	}
 
 	if (request) {
-		u8	is_dma = 0;
-		bool	short_packet = false;
 
 		trace_musb_req_tx(req);
 
 		if (dma && (csr & MUSB_TXCSR_DMAENAB)) {
-			is_dma = 1;
 			csr |= MUSB_TXCSR_P_WZC_BITS;
 			csr &= ~(MUSB_TXCSR_DMAENAB | MUSB_TXCSR_P_UNDERRUN |
 				 MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_AUTOSET);

@@ -476,16 +473,8 @@ void musb_g_tx(struct musb *musb, u8 epnum)
 		 */
 		if ((request->zero && request->length)
 			&& (request->length % musb_ep->packet_sz == 0)
-			&& (request->actual == request->length))
-				short_packet = true;
+			&& (request->actual == request->length)) {
 
-		if ((musb_dma_inventra(musb) || musb_dma_ux500(musb)) &&
-			(is_dma && (!dma->desired_mode ||
-				(request->actual &
-					(musb_ep->packet_sz - 1)))))
-				short_packet = true;
-
-		if (short_packet) {
 			/*
 			 * On DMA completion, FIFO may not be
 			 * available yet...
drivers/usb/musb/musbhsdma.c +11 -10
index a688f7f87829..5fc6825745f2 100644
@@ -346,12 +346,10 @@ static irqreturn_t dma_controller_irq(int irq, void *private_data)
 				channel->status = MUSB_DMA_STATUS_FREE;
 
 				/* completed */
-				if ((devctl & MUSB_DEVCTL_HM)
-					&& (musb_channel->transmit)
-					&& ((channel->desired_mode == 0)
-					    || (channel->actual_len &
-					    (musb_channel->max_packet_sz - 1)))
-				    ) {
+				if (musb_channel->transmit &&
+					(!channel->desired_mode ||
+					(channel->actual_len %
+					    musb_channel->max_packet_sz))) {
 					u8  epnum  = musb_channel->epnum;
 					int offset = musb->io.ep_offset(epnum,
 								    MUSB_TXCSR);

@@ -363,11 +361,14 @@ static irqreturn_t dma_controller_irq(int irq, void *private_data)
 					 */
 					musb_ep_select(mbase, epnum);
 					txcsr = musb_readw(mbase, offset);
-					txcsr &= ~(MUSB_TXCSR_DMAENAB
+					if (channel->desired_mode == 1) {
+						txcsr &= ~(MUSB_TXCSR_DMAENAB
 							| MUSB_TXCSR_AUTOSET);
-					musb_writew(mbase, offset, txcsr);
-					/* Send out the packet */
-					txcsr &= ~MUSB_TXCSR_DMAMODE;
+						musb_writew(mbase, offset, txcsr);
+						/* Send out the packet */
+						txcsr &= ~MUSB_TXCSR_DMAMODE;
+						txcsr |= MUSB_TXCSR_DMAENAB;
+					}
 					txcsr |=  MUSB_TXCSR_TXPKTRDY;
 					musb_writew(mbase, offset, txcsr);
 				}