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authorOlof Johansson <olof@lixom.net>2012-11-26 06:34:34 +0100
committerOlof Johansson <olof@lixom.net>2012-11-26 06:34:34 +0100
commit0f9cb211ba5db93d488fe6b154138231fdd0e22d (patch)
tree293871b042e9ebc49b1d783f1b110eef541ddc97 /drivers/usb/musb
parentMerge branch 'next/cleanup-samsung-2' of git://git.kernel.org/pub/scm/linux/k... (diff)
parentLinux 3.7-rc7 (diff)
downloadlinux-0f9cb211ba5db93d488fe6b154138231fdd0e22d.tar.xz
linux-0f9cb211ba5db93d488fe6b154138231fdd0e22d.zip
Merge tag 'v3.7-rc7' into next/cleanup
Merging in mainline back to next/cleanup since it has collected a few conflicts between fixes going upstream and some of the cleanup patches. Git doesn't auto-resolve some of them, and they're mostly noise so let's take care of it locally. Conflicts are in: arch/arm/mach-omap2/omap_hwmod_44xx_data.c arch/arm/plat-omap/i2c.c drivers/video/omap2/dss/dss.c Signed-off-by: Olof Johansson <olof@lixom.net>
Diffstat (limited to 'drivers/usb/musb')
-rw-r--r--drivers/usb/musb/musb_gadget.c30
-rw-r--r--drivers/usb/musb/ux500.c2
2 files changed, 27 insertions, 5 deletions
diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index d0b87e7b4abf..b6b84dacc791 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -707,11 +707,12 @@ static void rxstate(struct musb *musb, struct musb_request *req)
fifo_count = musb_readw(epio, MUSB_RXCOUNT);
/*
- * use mode 1 only if we expect data of at least ep packet_sz
- * and have not yet received a short packet
+ * Enable Mode 1 on RX transfers only when short_not_ok flag
+ * is set. Currently short_not_ok flag is set only from
+ * file_storage and f_mass_storage drivers
*/
- if ((request->length - request->actual >= musb_ep->packet_sz) &&
- (fifo_count >= musb_ep->packet_sz))
+
+ if (request->short_not_ok && fifo_count == musb_ep->packet_sz)
use_mode_1 = 1;
else
use_mode_1 = 0;
@@ -727,6 +728,27 @@ static void rxstate(struct musb *musb, struct musb_request *req)
c = musb->dma_controller;
channel = musb_ep->dma;
+ /* We use DMA Req mode 0 in rx_csr, and DMA controller operates in
+ * mode 0 only. So we do not get endpoint interrupts due to DMA
+ * completion. We only get interrupts from DMA controller.
+ *
+ * We could operate in DMA mode 1 if we knew the size of the tranfer
+ * in advance. For mass storage class, request->length = what the host
+ * sends, so that'd work. But for pretty much everything else,
+ * request->length is routinely more than what the host sends. For
+ * most these gadgets, end of is signified either by a short packet,
+ * or filling the last byte of the buffer. (Sending extra data in
+ * that last pckate should trigger an overflow fault.) But in mode 1,
+ * we don't get DMA completion interrupt for short packets.
+ *
+ * Theoretically, we could enable DMAReq irq (MUSB_RXCSR_DMAMODE = 1),
+ * to get endpoint interrupt on every DMA req, but that didn't seem
+ * to work reliably.
+ *
+ * REVISIT an updated g_file_storage can set req->short_not_ok, which
+ * then becomes usable as a runtime "use mode 1" hint...
+ */
+
/* Experimental: Mode1 works with mass storage use cases */
if (use_mode_1) {
csr |= MUSB_RXCSR_AUTOCLEAR;
diff --git a/drivers/usb/musb/ux500.c b/drivers/usb/musb/ux500.c
index d62a91fedc22..0e62f504410e 100644
--- a/drivers/usb/musb/ux500.c
+++ b/drivers/usb/musb/ux500.c
@@ -65,7 +65,7 @@ static int __devinit ux500_probe(struct platform_device *pdev)
struct platform_device *musb;
struct ux500_glue *glue;
struct clk *clk;
-
+ int musbid;
int ret = -ENOMEM;
glue = kzalloc(sizeof(*glue), GFP_KERNEL);