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path: root/drivers/usb/musb/musb_cppi41.c
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2015-02-13Reset to 3.12.37Scott Wood
2013-12-20usb: musb: musb_cppi41: handle pre-mature TX complete interruptSebastian Andrzej Siewior
commit a655f481d83d6d37bec0a2ddfdd24c30ff8f541f upstream. The TX-complete interrupt of the CPPI41 on AM335x fires too early. Adding a loop and counting how long it takes until the MUSB_TXCSR_TXPKTRDY bit is cleared I see FS: |musb-hdrc musb-hdrc.0.auto: configure ep1/80 packet_sz=64, mode=0, dma_addr=0xadc54002, len=1514 is_tx=1 |cppi41_dma_callback() 74 loops |musb-hdrc musb-hdrc.0.auto: configure ep1/80 packet_sz=64, mode=0, dma_addr=0xadcd8802, len=1514 is_tx=1 |cppi41_dma_callback() 66 loops |musb-hdrc musb-hdrc.0.auto: configure ep1/80 packet_sz=64, mode=0, dma_addr=0xadcd8002, len=1514 is_tx=1 |cppi41_dma_callback() 136 loops |musb-hdrc musb-hdrc.0.auto: configure ep1/80 packet_sz=64, mode=0, dma_addr=0xadf55802, len=1514 is_tx=1 |cppi41_dma_callback() 136 loops avg: 110 - 150us HS: |musb-hdrc musb-hdrc.0.auto: configure ep1/80 packet_sz=512, mode=0, dma_addr=0xaca6f002, len=1514 is_tx=1 |cppi41_dma_callback() 0 loops |musb-hdrc musb-hdrc.0.auto: configure ep1/80 packet_sz=512, mode=0, dma_addr=0xadd6f802, len=1514 is_tx=1 |cppi41_dma_callback() 2 loops |musb-hdrc musb-hdrc.0.auto: configure ep1/80 packet_sz=512, mode=0, dma_addr=0xadd6f002, len=1514 is_tx=1 |cppi41_dma_callback() 13 loops avg: 2us for the same test case. One loop means a udelay(1). The delay seems to depend on the packet size. On HS the bit is always cleared for small packet sizes while on FS it is never the case, it mostly around 110us. This testing has been performed with g_ether (musb as device) and using BULK transfers. INTR transfers are way more fun: during init the gadget sends a INT packet to the host and cppi41 says "transfer done" shortly after. The MUSB_TXCSR_TXPKTRDY bit is set even seconds later. The reason is that the host did not try to receive it, it does so after the interface (on host side) has been configured. Until this happens, that packet remains in musb's FIFO. To fix this, two things are done: - No DMA transfers for INT based endpoints. These transfer are usually very small and rare so it is likely better to skip the DMA engine and stuff the four bytes directly into the FIFO - on HS we poll up to 25us and hope that bit goes away. If not we setup a hrtimer to poll for it. The 140us delay is a rule of thumb. In FS the command | ping 10.10.10.10 -c1 -s65130 creates about 44 1514bytes transfers. About 19 of them need a second timer to complete. Reported-by: Bin Liu <b-liu@ti.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-20usb: musb: musb_cppi41: factor most of cppi41_dma_callback() into ↵Sebastian Andrzej Siewior
cppi41_trans_done() commit d373a8534d5e1e7a350e40d3c11961a7cd8d530b upstream. This patch moves most of the logic in cppi41_dma_callback() into cppi41_trans_done() where it can be called from another function. Instead of computing "transferred" (the number of bytes transferred in the last transaction) in cppi41_trans_done() the member "cppi41_channel->prog_len" is now set to 0 if the transfer as a whole can be considered as done. If it is != 0 then the next iteration is assumed. This is a preparation for a workaround. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-27usb: musb: cppi41: fix missing unlock on error in cppi41_dma_callback()Wei Yongjun
Add the missing unlock before return from function cppi41_dma_callback() in the error handling case. Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Felipe Balbi <balbi@ti.com>
2013-08-13usb: musb: cppi41: Enable in device-TX modeSebastian Andrzej Siewior
Since the musb-gadget code now calls the dma engine properly it is possible to enable it for the TX path in device mode. AM335x Advisory 1.0.13 says that we may lose the toggle bit on multiple RX transfers. There is a workaround in host mode but none in device mode and therefore RX transfers are disabled. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Felipe Balbi <balbi@ti.com>
2013-08-09usb: musb dma: add cppi41 dma driverSebastian Andrzej Siewior
This driver is currently used by musb' cppi41 couter part. I may merge both dma engine user of musb at some point but not just yet. The driver seems to work in RX/TX mode in host mode, tested on mass storage. I increaed the size of the TX / RX transfers and waited for the core code to cancel a transfers and it seems to recover. v2..3: - use mall transfers on RX side and check data toggle. - use rndis mode on tx side so we haveon interrupt for 4096 transfers. - remove custom "transferred" hack and use dmaengine_tx_status() to compute the total amount of data that has been transferred. - cancel transfers and reclaim descriptors v1..v2: - RX path added - dma mode 0 & 1 is working - device tree nodes re-created. Cc: Vinod Koul <vinod.koul@intel.com> Cc: Dan Williams <djbw@fb.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Felipe Balbi <balbi@ti.com>