From 793ae66c7dcc7e6655029f6613221a111b15b58e Mon Sep 17 00:00:00 2001 From: Sinan Kaya Date: Wed, 31 Aug 2016 11:10:29 -0400 Subject: [PATCH] dmaengine: qcom_hidma: add error reporting for tx_status The HIDMA driver is capable of error detection. However, the error was not being passed back to the client when tx_status API is called. Changing the error handling behavior to follow this oder. 1. dmaengine asserts error interrupt 2. Driver receives and mark's the txn as error 3. Driver completes the txn and intimates the client. No further submissions. Drop the locks before calling callback, as subsequent processing by client maybe in callback thread. 4. Client invokes status and you can return error 5. On error, client calls terminate_all. You can reset channel, free all descriptors in the active, pending and completed lists 6. Client prepares new txn and so on. As part of this work, got rid of the reset in the interrupt handler when an error happens and the HW is put into disabled state. The only way to recover is for the client to terminate the channel. Signed-off-by: Sinan Kaya Signed-off-by: Vinod Koul --- drivers/dma/qcom/hidma.c | 30 +++++++++++++++++++++++++----- drivers/dma/qcom/hidma.h | 2 +- drivers/dma/qcom/hidma_ll.c | 32 +++++++------------------------- 3 files changed, 33 insertions(+), 31 deletions(-) diff --git a/drivers/dma/qcom/hidma.c b/drivers/dma/qcom/hidma.c index ea24863794b9..e244e10a94b5 100644 --- a/drivers/dma/qcom/hidma.c +++ b/drivers/dma/qcom/hidma.c @@ -129,6 +129,7 @@ static void hidma_process_completed(struct hidma_chan *mchan) struct dmaengine_result result; desc = &mdesc->desc; + last_cookie = desc->cookie; spin_lock_irqsave(&mchan->lock, irqflags); dma_cookie_complete(desc); @@ -137,15 +138,15 @@ static void hidma_process_completed(struct hidma_chan *mchan) llstat = hidma_ll_status(mdma->lldev, mdesc->tre_ch); dmaengine_desc_get_callback(desc, &cb); - last_cookie = desc->cookie; dma_run_dependencies(desc); spin_lock_irqsave(&mchan->lock, irqflags); list_move(&mdesc->node, &mchan->free); - if (llstat == DMA_COMPLETE) + if (llstat == DMA_COMPLETE) { + mchan->last_success = last_cookie; result.result = DMA_TRANS_NOERROR; - else + } else result.result = DMA_TRANS_ABORTED; spin_unlock_irqrestore(&mchan->lock, irqflags); @@ -246,6 +247,19 @@ static void hidma_issue_pending(struct dma_chan *dmach) hidma_ll_start(dmadev->lldev); } +static inline bool hidma_txn_is_success(dma_cookie_t cookie, + dma_cookie_t last_success, dma_cookie_t last_used) +{ + if (last_success <= last_used) { + if ((cookie <= last_success) || (cookie > last_used)) + return true; + } else { + if ((cookie <= last_success) && (cookie > last_used)) + return true; + } + return false; +} + static enum dma_status hidma_tx_status(struct dma_chan *dmach, dma_cookie_t cookie, struct dma_tx_state *txstate) @@ -254,8 +268,13 @@ static enum dma_status hidma_tx_status(struct dma_chan *dmach, enum dma_status ret; ret = dma_cookie_status(dmach, cookie, txstate); - if (ret == DMA_COMPLETE) - return ret; + if (ret == DMA_COMPLETE) { + bool is_success; + + is_success = hidma_txn_is_success(cookie, mchan->last_success, + dmach->cookie); + return is_success ? ret : DMA_ERROR; + } if (mchan->paused && (ret == DMA_IN_PROGRESS)) { unsigned long flags; @@ -406,6 +425,7 @@ static int hidma_terminate_channel(struct dma_chan *chan) hidma_process_completed(mchan); spin_lock_irqsave(&mchan->lock, irqflags); + mchan->last_success = 0; list_splice_init(&mchan->active, &list); list_splice_init(&mchan->prepared, &list); list_splice_init(&mchan->completed, &list); diff --git a/drivers/dma/qcom/hidma.h b/drivers/dma/qcom/hidma.h index db413a5efc4e..e52e20716303 100644 --- a/drivers/dma/qcom/hidma.h +++ b/drivers/dma/qcom/hidma.h @@ -72,7 +72,6 @@ struct hidma_lldev { u32 tre_write_offset; /* TRE write location */ struct tasklet_struct task; /* task delivering notifications */ - struct tasklet_struct rst_task; /* task to reset HW */ DECLARE_KFIFO_PTR(handoff_fifo, struct hidma_tre *); /* pending TREs FIFO */ }; @@ -89,6 +88,7 @@ struct hidma_chan { bool allocated; char dbg_name[16]; u32 dma_sig; + dma_cookie_t last_success; /* * active descriptor on this channel diff --git a/drivers/dma/qcom/hidma_ll.c b/drivers/dma/qcom/hidma_ll.c index ad20dfb64c71..3224f24c577b 100644 --- a/drivers/dma/qcom/hidma_ll.c +++ b/drivers/dma/qcom/hidma_ll.c @@ -380,27 +380,6 @@ static int hidma_ll_reset(struct hidma_lldev *lldev) return 0; } -/* - * Abort all transactions and perform a reset. - */ -static void hidma_ll_abort(unsigned long arg) -{ - struct hidma_lldev *lldev = (struct hidma_lldev *)arg; - u8 err_code = HIDMA_EVRE_STATUS_ERROR; - u8 err_info = 0xFF; - int rc; - - hidma_cleanup_pending_tre(lldev, err_info, err_code); - - /* reset the channel for recovery */ - rc = hidma_ll_setup(lldev); - if (rc) { - dev_err(lldev->dev, "channel reinitialize failed after error\n"); - return; - } - writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_EN_REG); -} - /* * The interrupt handler for HIDMA will try to consume as many pending * EVRE from the event queue as possible. Each EVRE has an associated @@ -454,13 +433,18 @@ irqreturn_t hidma_ll_inthandler(int chirq, void *arg) while (cause) { if (cause & HIDMA_ERR_INT_MASK) { - dev_err(lldev->dev, "error 0x%x, resetting...\n", + dev_err(lldev->dev, "error 0x%x, disabling...\n", cause); /* Clear out pending interrupts */ writel(cause, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG); - tasklet_schedule(&lldev->rst_task); + /* No further submissions. */ + hidma_ll_disable(lldev); + + /* Driver completes the txn and intimates the client.*/ + hidma_cleanup_pending_tre(lldev, 0xFF, + HIDMA_EVRE_STATUS_ERROR); goto out; } @@ -808,7 +792,6 @@ struct hidma_lldev *hidma_ll_init(struct device *dev, u32 nr_tres, return NULL; spin_lock_init(&lldev->lock); - tasklet_init(&lldev->rst_task, hidma_ll_abort, (unsigned long)lldev); tasklet_init(&lldev->task, hidma_ll_tre_complete, (unsigned long)lldev); lldev->initialized = 1; writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_EN_REG); @@ -831,7 +814,6 @@ int hidma_ll_uninit(struct hidma_lldev *lldev) required_bytes = sizeof(struct hidma_tre) * lldev->nr_tres; tasklet_kill(&lldev->task); - tasklet_kill(&lldev->rst_task); memset(lldev->trepool, 0, required_bytes); lldev->trepool = NULL; lldev->pending_tre_count = 0; -- 2.20.1