From 2001f67e47ee3b0d822e2c738da5c4c33a31a7ea Mon Sep 17 00:00:00 2001 From: George Cherian Date: Thu, 27 Feb 2014 09:29:33 +0530 Subject: [PATCH] Revert "usb: musb: musb_cppi41: Revert the Advisory 1.0.13 workaround" Reverting the Advisory 1.0.13 leads to functional issues when multiple Mass Storage devices are connected. Especially when more than 3 Mass Storage disks are connected it fails to mount the disks reliably. This reverts commit c424ef3e2beb89488e7e597446b4c6bc8f1852c5. Signed-off-by: George Cherian Reported-by: Roger Quadros --- drivers/usb/musb/musb_cppi41.c | 96 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 79 insertions(+), 17 deletions(-) diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c index d02facc..01df8f9 100644 --- a/drivers/usb/musb/musb_cppi41.c +++ b/drivers/usb/musb/musb_cppi41.c @@ -31,6 +31,7 @@ struct cppi41_dma_channel { u8 port_num; u8 is_tx; u8 is_allocated; + u8 usb_toggle; dma_addr_t buf_addr; u32 total_len; @@ -55,6 +56,50 @@ struct cppi41_dma_controller { u32 auto_req; }; +static void save_rx_toggle(struct cppi41_dma_channel *cppi41_channel) +{ + u16 csr; + u8 toggle; + + if (cppi41_channel->is_tx) + return; + if (!is_host_active(cppi41_channel->controller->musb)) + return; + + csr = musb_readw(cppi41_channel->hw_ep->regs, MUSB_RXCSR); + toggle = csr & MUSB_RXCSR_H_DATATOGGLE ? 1 : 0; + + cppi41_channel->usb_toggle = toggle; +} + +static void update_rx_toggle(struct cppi41_dma_channel *cppi41_channel) +{ + u16 csr; + u8 toggle; + + if (cppi41_channel->is_tx) + return; + if (!is_host_active(cppi41_channel->controller->musb)) + return; + + csr = musb_readw(cppi41_channel->hw_ep->regs, MUSB_RXCSR); + toggle = csr & MUSB_RXCSR_H_DATATOGGLE ? 1 : 0; + + /* + * AM335x Advisory 1.0.13: Due to internal synchronisation error the + * data toggle may reset from DATA1 to DATA0 during receiving data from + * more than one endpoint. + */ + if (!toggle && toggle == cppi41_channel->usb_toggle) { + csr |= MUSB_RXCSR_H_DATATOGGLE | MUSB_RXCSR_H_WR_DATATOGGLE; + musb_writew(cppi41_channel->hw_ep->regs, MUSB_RXCSR, csr); + dev_dbg(cppi41_channel->controller->musb->controller, + "Restoring DATA1 toggle.\n"); + } + + cppi41_channel->usb_toggle = toggle; +} + static bool musb_is_tx_fifo_empty(struct musb_hw_ep *hw_ep) { u8 epnum = hw_ep->epnum; @@ -217,6 +262,8 @@ static void cppi41_dma_callback(void *private_data) hw_ep->epnum, cppi41_channel->transferred, cppi41_channel->total_len); + update_rx_toggle(cppi41_channel); + if (cppi41_channel->transferred == cppi41_channel->total_len || transferred < cppi41_channel->packet_sz) cppi41_channel->prog_len = 0; @@ -347,6 +394,7 @@ static bool cppi41_configure_channel(struct dma_channel *channel, struct dma_async_tx_descriptor *dma_desc; enum dma_transfer_direction direction; struct musb *musb = cppi41_channel->controller->musb; + unsigned use_gen_rndis = 0; dev_dbg(musb->controller, "configure ep%d/%x packet_sz=%d, mode=%d, dma_addr=0x%llx, len=%d is_tx=%d\n", @@ -359,26 +407,39 @@ static bool cppi41_configure_channel(struct dma_channel *channel, cppi41_channel->transferred = 0; cppi41_channel->packet_sz = packet_sz; - /* RNDIS mode */ - if (len > packet_sz) { - musb_writel(musb->ctrl_base, - RNDIS_REG(cppi41_channel->port_num), len); - /* gen rndis */ - cppi41_set_dma_mode(cppi41_channel, - EP_MODE_DMA_GEN_RNDIS); - - /* auto req */ - cppi41_set_autoreq_mode(cppi41_channel, + /* + * Due to AM335x' Advisory 1.0.13 we are not allowed to transfer more + * than max packet size at a time. + */ + if (cppi41_channel->is_tx) + use_gen_rndis = 1; + + if (use_gen_rndis) { + /* RNDIS mode */ + if (len > packet_sz) { + musb_writel(musb->ctrl_base, + RNDIS_REG(cppi41_channel->port_num), len); + /* gen rndis */ + cppi41_set_dma_mode(cppi41_channel, + EP_MODE_DMA_GEN_RNDIS); + + /* auto req */ + cppi41_set_autoreq_mode(cppi41_channel, EP_MODE_AUTOREG_ALL_NEOP); - } else { - musb_writel(musb->ctrl_base, - RNDIS_REG(cppi41_channel->port_num), 0); - cppi41_set_dma_mode(cppi41_channel, - EP_MODE_DMA_TRANSPARENT); - cppi41_set_autoreq_mode(cppi41_channel, + } else { + musb_writel(musb->ctrl_base, + RNDIS_REG(cppi41_channel->port_num), 0); + cppi41_set_dma_mode(cppi41_channel, + EP_MODE_DMA_TRANSPARENT); + cppi41_set_autoreq_mode(cppi41_channel, EP_MODE_AUTOREG_NONE); + } + } else { + /* fallback mode */ + cppi41_set_dma_mode(cppi41_channel, EP_MODE_DMA_TRANSPARENT); + cppi41_set_autoreq_mode(cppi41_channel, EP_MODE_AUTOREG_NONE); + len = min_t(u32, packet_sz, len); } - cppi41_channel->prog_len = len; direction = cppi41_channel->is_tx ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM; dma_desc = dmaengine_prep_slave_single(dc, dma_addr, len, direction, @@ -390,6 +451,7 @@ static bool cppi41_configure_channel(struct dma_channel *channel, dma_desc->callback_param = channel; cppi41_channel->cookie = dma_desc->tx_submit(dma_desc); + save_rx_toggle(cppi41_channel); dma_async_issue_pending(dc); return true; } -- 1.9.1