8 files changed, 260 insertions, 117 deletions

diff --git a/drivers/bus/mhi/ep/internal.h b/drivers/bus/mhi/ep/internal.h
index a2125fa5fe..577965f95f 100644
--- a/drivers/bus/mhi/ep/internal.h
+++ b/drivers/bus/mhi/ep/internal.h
@@ -126,6 +126,7 @@ struct mhi_ep_ring {
 	union mhi_ep_ring_ctx *ring_ctx;
 	struct mhi_ring_element *ring_cache;
 	enum mhi_ep_ring_type type;
+	struct delayed_work intmodt_work;
 	u64 rbase;
 	size_t rd_offset;
 	size_t wr_offset;
@@ -135,7 +136,9 @@ struct mhi_ep_ring {
 	u32 ch_id;
 	u32 er_index;
 	u32 irq_vector;
+	u32 intmodt;
 	bool started;
+	bool irq_pending;
 };
 
 struct mhi_ep_cmd {
@@ -159,6 +162,7 @@ struct mhi_ep_chan {
 	void (*xfer_cb)(struct mhi_ep_device *mhi_dev, struct mhi_result *result);
 	enum mhi_ch_state state;
 	enum dma_data_direction dir;
+	size_t rd_offset;
 	u64 tre_loc;
 	u32 tre_size;
 	u32 tre_bytes_left;
diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
index 934cdbca08..65f1f6b9b5 100644
--- a/drivers/bus/mhi/ep/main.c
+++ b/drivers/bus/mhi/ep/main.c
@@ -54,11 +54,27 @@ static int mhi_ep_send_event(struct mhi_ep_cntrl *mhi_cntrl, u32 ring_idx,
 	mutex_unlock(&mhi_cntrl->event_lock);
 
 	/*
-	 * Raise IRQ to host only if the BEI flag is not set in TRE. Host might
-	 * set this flag for interrupt moderation as per MHI protocol.
+	 * As per the MHI specification, section 4.3, Interrupt moderation:
+	 *
+	 * 1. If BEI flag is not set, cancel any pending intmodt work if started
+	 * for the event ring and raise IRQ immediately.
+	 *
+	 * 2. If both BEI and intmodt are set, and if no IRQ is pending for the
+	 * same event ring, start the IRQ delayed work as per the value of
+	 * intmodt. If previous IRQ is pending, then do nothing as the pending
+	 * IRQ is enough for the host to process the current event ring element.
+	 *
+	 * 3. If BEI is set and intmodt is not set, no need to raise IRQ.
 	 */
-	if (!bei)
+	if (!bei) {
+		if (READ_ONCE(ring->irq_pending))
+			cancel_delayed_work(&ring->intmodt_work);
+
 		mhi_cntrl->raise_irq(mhi_cntrl, ring->irq_vector);
+	} else if (ring->intmodt && !READ_ONCE(ring->irq_pending)) {
+		WRITE_ONCE(ring->irq_pending, true);
+		schedule_delayed_work(&ring->intmodt_work, msecs_to_jiffies(ring->intmodt));
+	}
 
 	return 0;
 
@@ -183,6 +199,8 @@ static int mhi_ep_process_cmd_ring(struct mhi_ep_ring *ring, struct mhi_ring_ele
 
 				goto err_unlock;
 			}
+
+			mhi_chan->rd_offset = ch_ring->rd_offset;
 		}
 
 		/* Set channel state to RUNNING */
@@ -312,21 +330,85 @@ bool mhi_ep_queue_is_empty(struct mhi_ep_device *mhi_dev, enum dma_data_directio
 	struct mhi_ep_cntrl *mhi_cntrl = mhi_dev->mhi_cntrl;
 	struct mhi_ep_ring *ring = &mhi_cntrl->mhi_chan[mhi_chan->chan].ring;
 
-	return !!(ring->rd_offset == ring->wr_offset);
+	return !!(mhi_chan->rd_offset == ring->wr_offset);
 }
 EXPORT_SYMBOL_GPL(mhi_ep_queue_is_empty);
 
+static void mhi_ep_read_completion(struct mhi_ep_buf_info *buf_info)
+{
+	struct mhi_ep_device *mhi_dev = buf_info->mhi_dev;
+	struct mhi_ep_cntrl *mhi_cntrl = mhi_dev->mhi_cntrl;
+	struct mhi_ep_chan *mhi_chan = mhi_dev->ul_chan;
+	struct mhi_ep_ring *ring = &mhi_cntrl->mhi_chan[mhi_chan->chan].ring;
+	struct mhi_ring_element *el = &ring->ring_cache[ring->rd_offset];
+	struct mhi_result result = {};
+	int ret;
+
+	if (mhi_chan->xfer_cb) {
+		result.buf_addr = buf_info->cb_buf;
+		result.dir = mhi_chan->dir;
+		result.bytes_xferd = buf_info->size;
+
+		mhi_chan->xfer_cb(mhi_dev, &result);
+	}
+
+	/*
+	 * The host will split the data packet into multiple TREs if it can't fit
+	 * the packet in a single TRE. In that case, CHAIN flag will be set by the
+	 * host for all TREs except the last one.
+	 */
+	if (buf_info->code != MHI_EV_CC_OVERFLOW) {
+		if (MHI_TRE_DATA_GET_CHAIN(el)) {
+			/*
+			 * IEOB (Interrupt on End of Block) flag will be set by the host if
+			 * it expects the completion event for all TREs of a TD.
+			 */
+			if (MHI_TRE_DATA_GET_IEOB(el)) {
+				ret = mhi_ep_send_completion_event(mhi_cntrl, ring, el,
+							     MHI_TRE_DATA_GET_LEN(el),
+							     MHI_EV_CC_EOB);
+				if (ret < 0) {
+					dev_err(&mhi_chan->mhi_dev->dev,
+						"Error sending transfer compl. event\n");
+					goto err_free_tre_buf;
+				}
+			}
+		} else {
+			/*
+			 * IEOT (Interrupt on End of Transfer) flag will be set by the host
+			 * for the last TRE of the TD and expects the completion event for
+			 * the same.
+			 */
+			if (MHI_TRE_DATA_GET_IEOT(el)) {
+				ret = mhi_ep_send_completion_event(mhi_cntrl, ring, el,
+							     MHI_TRE_DATA_GET_LEN(el),
+							     MHI_EV_CC_EOT);
+				if (ret < 0) {
+					dev_err(&mhi_chan->mhi_dev->dev,
+						"Error sending transfer compl. event\n");
+					goto err_free_tre_buf;
+				}
+			}
+		}
+	}
+
+	mhi_ep_ring_inc_index(ring);
+
+err_free_tre_buf:
+	kmem_cache_free(mhi_cntrl->tre_buf_cache, buf_info->cb_buf);
+}
+
 static int mhi_ep_read_channel(struct mhi_ep_cntrl *mhi_cntrl,
-				struct mhi_ep_ring *ring,
-				struct mhi_result *result,
-				u32 len)
+			       struct mhi_ep_ring *ring)
 {
 	struct mhi_ep_chan *mhi_chan = &mhi_cntrl->mhi_chan[ring->ch_id];
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
 	size_t tr_len, read_offset, write_offset;
 	struct mhi_ep_buf_info buf_info = {};
+	u32 len = MHI_EP_DEFAULT_MTU;
 	struct mhi_ring_element *el;
 	bool tr_done = false;
+	void *buf_addr;
 	u32 buf_left;
 	int ret;
 
@@ -339,7 +421,7 @@ static int mhi_ep_read_channel(struct mhi_ep_cntrl *mhi_cntrl,
 			return -ENODEV;
 		}
 
-		el = &ring->ring_cache[ring->rd_offset];
+		el = &ring->ring_cache[mhi_chan->rd_offset];
 
 		/* Check if there is data pending to be read from previous read operation */
 		if (mhi_chan->tre_bytes_left) {
@@ -356,82 +438,50 @@ static int mhi_ep_read_channel(struct mhi_ep_cntrl *mhi_cntrl,
 		read_offset = mhi_chan->tre_size - mhi_chan->tre_bytes_left;
 		write_offset = len - buf_left;
 
+		buf_addr = kmem_cache_zalloc(mhi_cntrl->tre_buf_cache, GFP_KERNEL | GFP_DMA);
+		if (!buf_addr)
+			return -ENOMEM;
+
 		buf_info.host_addr = mhi_chan->tre_loc + read_offset;
-		buf_info.dev_addr = result->buf_addr + write_offset;
+		buf_info.dev_addr = buf_addr + write_offset;
 		buf_info.size = tr_len;
+		buf_info.cb = mhi_ep_read_completion;
+		buf_info.cb_buf = buf_addr;
+		buf_info.mhi_dev = mhi_chan->mhi_dev;
+
+		if (mhi_chan->tre_bytes_left - tr_len)
+			buf_info.code = MHI_EV_CC_OVERFLOW;
 
 		dev_dbg(dev, "Reading %zd bytes from channel (%u)\n", tr_len, ring->ch_id);
-		ret = mhi_cntrl->read_from_host(mhi_cntrl, &buf_info);
+		ret = mhi_cntrl->read_async(mhi_cntrl, &buf_info);
 		if (ret < 0) {
 			dev_err(&mhi_chan->mhi_dev->dev, "Error reading from channel\n");
-			return ret;
+			goto err_free_buf_addr;
 		}
 
 		buf_left -= tr_len;
 		mhi_chan->tre_bytes_left -= tr_len;
 
-		/*
-		 * Once the TRE (Transfer Ring Element) of a TD (Transfer Descriptor) has been
-		 * read completely:
-		 *
-		 * 1. Send completion event to the host based on the flags set in TRE.
-		 * 2. Increment the local read offset of the transfer ring.
-		 */
 		if (!mhi_chan->tre_bytes_left) {
-			/*
-			 * The host will split the data packet into multiple TREs if it can't fit
-			 * the packet in a single TRE. In that case, CHAIN flag will be set by the
-			 * host for all TREs except the last one.
-			 */
-			if (MHI_TRE_DATA_GET_CHAIN(el)) {
-				/*
-				 * IEOB (Interrupt on End of Block) flag will be set by the host if
-				 * it expects the completion event for all TREs of a TD.
-				 */
-				if (MHI_TRE_DATA_GET_IEOB(el)) {
-					ret = mhi_ep_send_completion_event(mhi_cntrl, ring, el,
-								     MHI_TRE_DATA_GET_LEN(el),
-								     MHI_EV_CC_EOB);
-					if (ret < 0) {
-						dev_err(&mhi_chan->mhi_dev->dev,
-							"Error sending transfer compl. event\n");
-						return ret;
-					}
-				}
-			} else {
-				/*
-				 * IEOT (Interrupt on End of Transfer) flag will be set by the host
-				 * for the last TRE of the TD and expects the completion event for
-				 * the same.
-				 */
-				if (MHI_TRE_DATA_GET_IEOT(el)) {
-					ret = mhi_ep_send_completion_event(mhi_cntrl, ring, el,
-								     MHI_TRE_DATA_GET_LEN(el),
-								     MHI_EV_CC_EOT);
-					if (ret < 0) {
-						dev_err(&mhi_chan->mhi_dev->dev,
-							"Error sending transfer compl. event\n");
-						return ret;
-					}
-				}
-
+			if (MHI_TRE_DATA_GET_IEOT(el))
 				tr_done = true;
-			}
 
-			mhi_ep_ring_inc_index(ring);
+			mhi_chan->rd_offset = (mhi_chan->rd_offset + 1) % ring->ring_size;
 		}
-
-		result->bytes_xferd += tr_len;
 	} while (buf_left && !tr_done);
 
 	return 0;
+
+err_free_buf_addr:
+	kmem_cache_free(mhi_cntrl->tre_buf_cache, buf_addr);
+
+	return ret;
 }
 
-static int mhi_ep_process_ch_ring(struct mhi_ep_ring *ring, struct mhi_ring_element *el)
+static int mhi_ep_process_ch_ring(struct mhi_ep_ring *ring)
 {
 	struct mhi_ep_cntrl *mhi_cntrl = ring->mhi_cntrl;
 	struct mhi_result result = {};
-	u32 len = MHI_EP_DEFAULT_MTU;
 	struct mhi_ep_chan *mhi_chan;
 	int ret;
 
@@ -452,32 +502,49 @@ static int mhi_ep_process_ch_ring(struct mhi_ep_ring *ring, struct mhi_ring_elem
 		mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
 	} else {
 		/* UL channel */
-		result.buf_addr = kmem_cache_zalloc(mhi_cntrl->tre_buf_cache, GFP_KERNEL | GFP_DMA);
-		if (!result.buf_addr)
-			return -ENOMEM;
-
 		do {
-			ret = mhi_ep_read_channel(mhi_cntrl, ring, &result, len);
+			ret = mhi_ep_read_channel(mhi_cntrl, ring);
 			if (ret < 0) {
 				dev_err(&mhi_chan->mhi_dev->dev, "Failed to read channel\n");
-				kmem_cache_free(mhi_cntrl->tre_buf_cache, result.buf_addr);
 				return ret;
 			}
 
-			result.dir = mhi_chan->dir;
-			mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
-			result.bytes_xferd = 0;
-			memset(result.buf_addr, 0, len);
-
 			/* Read until the ring becomes empty */
 		} while (!mhi_ep_queue_is_empty(mhi_chan->mhi_dev, DMA_TO_DEVICE));
-
-		kmem_cache_free(mhi_cntrl->tre_buf_cache, result.buf_addr);
 	}
 
 	return 0;
 }
 
+static void mhi_ep_skb_completion(struct mhi_ep_buf_info *buf_info)
+{
+	struct mhi_ep_device *mhi_dev = buf_info->mhi_dev;
+	struct mhi_ep_cntrl *mhi_cntrl = mhi_dev->mhi_cntrl;
+	struct mhi_ep_chan *mhi_chan = mhi_dev->dl_chan;
+	struct mhi_ep_ring *ring = &mhi_cntrl->mhi_chan[mhi_chan->chan].ring;
+	struct mhi_ring_element *el = &ring->ring_cache[ring->rd_offset];
+	struct device *dev = &mhi_dev->dev;
+	struct mhi_result result = {};
+	int ret;
+
+	if (mhi_chan->xfer_cb) {
+		result.buf_addr = buf_info->cb_buf;
+		result.dir = mhi_chan->dir;
+		result.bytes_xferd = buf_info->size;
+
+		mhi_chan->xfer_cb(mhi_dev, &result);
+	}
+
+	ret = mhi_ep_send_completion_event(mhi_cntrl, ring, el, buf_info->size,
+					   buf_info->code);
+	if (ret) {
+		dev_err(dev, "Error sending transfer completion event\n");
+		return;
+	}
+
+	mhi_ep_ring_inc_index(ring);
+}
+
 /* TODO: Handle partially formed TDs */
 int mhi_ep_queue_skb(struct mhi_ep_device *mhi_dev, struct sk_buff *skb)
 {
@@ -488,7 +555,6 @@ int mhi_ep_queue_skb(struct mhi_ep_device *mhi_dev, struct sk_buff *skb)
 	struct mhi_ring_element *el;
 	u32 buf_left, read_offset;
 	struct mhi_ep_ring *ring;
-	enum mhi_ev_ccs code;
 	size_t tr_len;
 	u32 tre_len;
 	int ret;
@@ -512,7 +578,7 @@ int mhi_ep_queue_skb(struct mhi_ep_device *mhi_dev, struct sk_buff *skb)
 			goto err_exit;
 		}
 
-		el = &ring->ring_cache[ring->rd_offset];
+		el = &ring->ring_cache[mhi_chan->rd_offset];
 		tre_len = MHI_TRE_DATA_GET_LEN(el);
 
 		tr_len = min(buf_left, tre_len);
@@ -521,33 +587,35 @@ int mhi_ep_queue_skb(struct mhi_ep_device *mhi_dev, struct sk_buff *skb)
 		buf_info.dev_addr = skb->data + read_offset;
 		buf_info.host_addr = MHI_TRE_DATA_GET_PTR(el);
 		buf_info.size = tr_len;
+		buf_info.cb = mhi_ep_skb_completion;
+		buf_info.cb_buf = skb;
+		buf_info.mhi_dev = mhi_dev;
 
-		dev_dbg(dev, "Writing %zd bytes to channel (%u)\n", tr_len, ring->ch_id);
-		ret = mhi_cntrl->write_to_host(mhi_cntrl, &buf_info);
-		if (ret < 0) {
-			dev_err(dev, "Error writing to the channel\n");
-			goto err_exit;
-		}
-
-		buf_left -= tr_len;
 		/*
 		 * For all TREs queued by the host for DL channel, only the EOT flag will be set.
 		 * If the packet doesn't fit into a single TRE, send the OVERFLOW event to
 		 * the host so that the host can adjust the packet boundary to next TREs. Else send
 		 * the EOT event to the host indicating the packet boundary.
 		 */
-		if (buf_left)
-			code = MHI_EV_CC_OVERFLOW;
+		if (buf_left - tr_len)
+			buf_info.code = MHI_EV_CC_OVERFLOW;
 		else
-			code = MHI_EV_CC_EOT;
+			buf_info.code = MHI_EV_CC_EOT;
 
-		ret = mhi_ep_send_completion_event(mhi_cntrl, ring, el, tr_len, code);
-		if (ret) {
-			dev_err(dev, "Error sending transfer completion event\n");
+		dev_dbg(dev, "Writing %zd bytes to channel (%u)\n", tr_len, ring->ch_id);
+		ret = mhi_cntrl->write_async(mhi_cntrl, &buf_info);
+		if (ret < 0) {
+			dev_err(dev, "Error writing to the channel\n");
 			goto err_exit;
 		}
 
-		mhi_ep_ring_inc_index(ring);
+		buf_left -= tr_len;
+
+		/*
+		 * Update the read offset cached in mhi_chan. Actual read offset
+		 * will be updated by the completion handler.
+		 */
+		mhi_chan->rd_offset = (mhi_chan->rd_offset + 1) % ring->ring_size;
 	} while (buf_left);
 
 	mutex_unlock(&mhi_chan->lock);
@@ -748,7 +816,6 @@ static void mhi_ep_ch_ring_worker(struct work_struct *work)
 	struct mhi_ep_cntrl *mhi_cntrl = container_of(work, struct mhi_ep_cntrl, ch_ring_work);
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
 	struct mhi_ep_ring_item *itr, *tmp;
-	struct mhi_ring_element *el;
 	struct mhi_ep_ring *ring;
 	struct mhi_ep_chan *chan;
 	unsigned long flags;
@@ -787,16 +854,14 @@ static void mhi_ep_ch_ring_worker(struct work_struct *work)
 		}
 
 		/* Sanity check to make sure there are elements in the ring */
-		if (ring->rd_offset == ring->wr_offset) {
+		if (chan->rd_offset == ring->wr_offset) {
 			mutex_unlock(&chan->lock);
 			kmem_cache_free(mhi_cntrl->ring_item_cache, itr);
 			continue;
 		}
 
-		el = &ring->ring_cache[ring->rd_offset];
-
 		dev_dbg(dev, "Processing the ring for channel (%u)\n", ring->ch_id);
-		ret = mhi_ep_process_ch_ring(ring, el);
+		ret = mhi_ep_process_ch_ring(ring);
 		if (ret) {
 			dev_err(dev, "Error processing ring for channel (%u): %d\n",
 				ring->ch_id, ret);
@@ -1399,6 +1464,10 @@ int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl,
 	if (!mhi_cntrl || !mhi_cntrl->cntrl_dev || !mhi_cntrl->mmio || !mhi_cntrl->irq)
 		return -EINVAL;
 
+	if (!mhi_cntrl->read_sync || !mhi_cntrl->write_sync ||
+	    !mhi_cntrl->read_async || !mhi_cntrl->write_async)
+		return -EINVAL;
+
 	ret = mhi_ep_chan_init(mhi_cntrl, config);
 	if (ret)
 		return ret;
@@ -1431,6 +1500,7 @@ int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl,
 		ret = -ENOMEM;
 		goto err_destroy_tre_buf_cache;
 	}
+
 	INIT_WORK(&mhi_cntrl->state_work, mhi_ep_state_worker);
 	INIT_WORK(&mhi_cntrl->reset_work, mhi_ep_reset_worker);
 	INIT_WORK(&mhi_cntrl->cmd_ring_work, mhi_ep_cmd_ring_worker);
diff --git a/drivers/bus/mhi/ep/ring.c b/drivers/bus/mhi/ep/ring.c
index c673d7200b..aeb53b2c34 100644
--- a/drivers/bus/mhi/ep/ring.c
+++ b/drivers/bus/mhi/ep/ring.c
@@ -48,7 +48,7 @@ static int __mhi_ep_cache_ring(struct mhi_ep_ring *ring, size_t end)
 		buf_info.host_addr = ring->rbase + (start * sizeof(struct mhi_ring_element));
 		buf_info.dev_addr = &ring->ring_cache[start];
 
-		ret = mhi_cntrl->read_from_host(mhi_cntrl, &buf_info);
+		ret = mhi_cntrl->read_sync(mhi_cntrl, &buf_info);
 		if (ret < 0)
 			return ret;
 	} else {
@@ -56,7 +56,7 @@ static int __mhi_ep_cache_ring(struct mhi_ep_ring *ring, size_t end)
 		buf_info.host_addr = ring->rbase + (start * sizeof(struct mhi_ring_element));
 		buf_info.dev_addr = &ring->ring_cache[start];
 
-		ret = mhi_cntrl->read_from_host(mhi_cntrl, &buf_info);
+		ret = mhi_cntrl->read_sync(mhi_cntrl, &buf_info);
 		if (ret < 0)
 			return ret;
 
@@ -65,7 +65,7 @@ static int __mhi_ep_cache_ring(struct mhi_ep_ring *ring, size_t end)
 			buf_info.dev_addr = &ring->ring_cache[0];
 			buf_info.size = end * sizeof(struct mhi_ring_element);
 
-			ret = mhi_cntrl->read_from_host(mhi_cntrl, &buf_info);
+			ret = mhi_cntrl->read_sync(mhi_cntrl, &buf_info);
 			if (ret < 0)
 				return ret;
 		}
@@ -143,7 +143,7 @@ int mhi_ep_ring_add_element(struct mhi_ep_ring *ring, struct mhi_ring_element *e
 	buf_info.dev_addr = el;
 	buf_info.size = sizeof(*el);
 
-	return mhi_cntrl->write_to_host(mhi_cntrl, &buf_info);
+	return mhi_cntrl->write_sync(mhi_cntrl, &buf_info);
 }
 
 void mhi_ep_ring_init(struct mhi_ep_ring *ring, enum mhi_ep_ring_type type, u32 id)
@@ -162,6 +162,15 @@ void mhi_ep_ring_init(struct mhi_ep_ring *ring, enum mhi_ep_ring_type type, u32
 	}
 }
 
+static void mhi_ep_raise_irq(struct work_struct *work)
+{
+	struct mhi_ep_ring *ring = container_of(work, struct mhi_ep_ring, intmodt_work.work);
+	struct mhi_ep_cntrl *mhi_cntrl = ring->mhi_cntrl;
+
+	mhi_cntrl->raise_irq(mhi_cntrl, ring->irq_vector);
+	WRITE_ONCE(ring->irq_pending, false);
+}
+
 int mhi_ep_ring_start(struct mhi_ep_cntrl *mhi_cntrl, struct mhi_ep_ring *ring,
 			union mhi_ep_ring_ctx *ctx)
 {
@@ -178,8 +187,13 @@ int mhi_ep_ring_start(struct mhi_ep_cntrl *mhi_cntrl, struct mhi_ep_ring *ring,
 	if (ring->type == RING_TYPE_CH)
 		ring->er_index = le32_to_cpu(ring->ring_ctx->ch.erindex);
 
-	if (ring->type == RING_TYPE_ER)
+	if (ring->type == RING_TYPE_ER) {
 		ring->irq_vector = le32_to_cpu(ring->ring_ctx->ev.msivec);
+		ring->intmodt = FIELD_GET(EV_CTX_INTMODT_MASK,
+					  le32_to_cpu(ring->ring_ctx->ev.intmod));
+
+		INIT_DELAYED_WORK(&ring->intmodt_work, mhi_ep_raise_irq);
+	}
 
 	/* During ring init, both rp and wp are equal */
 	memcpy_fromio(&val, (void __iomem *) &ring->ring_ctx->generic.rp, sizeof(u64));
@@ -206,6 +220,9 @@ int mhi_ep_ring_start(struct mhi_ep_cntrl *mhi_cntrl, struct mhi_ep_ring *ring,
 
 void mhi_ep_ring_reset(struct mhi_ep_cntrl *mhi_cntrl, struct mhi_ep_ring *ring)
 {
+	if (ring->type == RING_TYPE_ER)
+		cancel_delayed_work_sync(&ring->intmodt_work);
+
 	ring->started = false;
 	kfree(ring->ring_cache);
 	ring->ring_cache = NULL;
diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
index f78aefd2d7..8e5ec1a409 100644
--- a/drivers/bus/mhi/host/init.c
+++ b/drivers/bus/mhi/host/init.c
@@ -62,6 +62,7 @@ static const char * const mhi_pm_state_str[] = {
 	[MHI_PM_STATE_FW_DL_ERR] = "Firmware Download Error",
 	[MHI_PM_STATE_SYS_ERR_DETECT] = "SYS ERROR Detect",
 	[MHI_PM_STATE_SYS_ERR_PROCESS] = "SYS ERROR Process",
+	[MHI_PM_STATE_SYS_ERR_FAIL] = "SYS ERROR Failure",
 	[MHI_PM_STATE_SHUTDOWN_PROCESS] = "SHUTDOWN Process",
 	[MHI_PM_STATE_LD_ERR_FATAL_DETECT] = "Linkdown or Error Fatal Detect",
 };
@@ -881,6 +882,7 @@ static int parse_config(struct mhi_controller *mhi_cntrl,
 	if (!mhi_cntrl->timeout_ms)
 		mhi_cntrl->timeout_ms = MHI_TIMEOUT_MS;
 
+	mhi_cntrl->ready_timeout_ms = config->ready_timeout_ms;
 	mhi_cntrl->bounce_buf = config->use_bounce_buf;
 	mhi_cntrl->buffer_len = config->buf_len;
 	if (!mhi_cntrl->buffer_len)
diff --git a/drivers/bus/mhi/host/internal.h b/drivers/bus/mhi/host/internal.h
index 2e139e76de..4b6deea17b 100644
--- a/drivers/bus/mhi/host/internal.h
+++ b/drivers/bus/mhi/host/internal.h
@@ -88,6 +88,7 @@ enum mhi_pm_state {
 	MHI_PM_STATE_FW_DL_ERR,
 	MHI_PM_STATE_SYS_ERR_DETECT,
 	MHI_PM_STATE_SYS_ERR_PROCESS,
+	MHI_PM_STATE_SYS_ERR_FAIL,
 	MHI_PM_STATE_SHUTDOWN_PROCESS,
 	MHI_PM_STATE_LD_ERR_FATAL_DETECT,
 	MHI_PM_STATE_MAX
@@ -104,14 +105,16 @@ enum mhi_pm_state {
 #define MHI_PM_FW_DL_ERR				BIT(7)
 #define MHI_PM_SYS_ERR_DETECT				BIT(8)
 #define MHI_PM_SYS_ERR_PROCESS				BIT(9)
-#define MHI_PM_SHUTDOWN_PROCESS				BIT(10)
+#define MHI_PM_SYS_ERR_FAIL				BIT(10)
+#define MHI_PM_SHUTDOWN_PROCESS				BIT(11)
 /* link not accessible */
-#define MHI_PM_LD_ERR_FATAL_DETECT			BIT(11)
+#define MHI_PM_LD_ERR_FATAL_DETECT			BIT(12)
 
 #define MHI_REG_ACCESS_VALID(pm_state)			((pm_state & (MHI_PM_POR | MHI_PM_M0 | \
 						MHI_PM_M2 | MHI_PM_M3_ENTER | MHI_PM_M3_EXIT | \
 						MHI_PM_SYS_ERR_DETECT | MHI_PM_SYS_ERR_PROCESS | \
-						MHI_PM_SHUTDOWN_PROCESS | MHI_PM_FW_DL_ERR)))
+						MHI_PM_SYS_ERR_FAIL | MHI_PM_SHUTDOWN_PROCESS |  \
+						MHI_PM_FW_DL_ERR)))
 #define MHI_PM_IN_ERROR_STATE(pm_state)			(pm_state >= MHI_PM_FW_DL_ERR)
 #define MHI_PM_IN_FATAL_STATE(pm_state)			(pm_state == MHI_PM_LD_ERR_FATAL_DETECT)
 #define MHI_DB_ACCESS_VALID(mhi_cntrl)			(mhi_cntrl->pm_state & mhi_cntrl->db_access)
@@ -321,7 +324,7 @@ int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl,
 				    u32 *out);
 int __must_check mhi_poll_reg_field(struct mhi_controller *mhi_cntrl,
 				    void __iomem *base, u32 offset, u32 mask,
-				    u32 val, u32 delayus);
+				    u32 val, u32 delayus, u32 timeout_ms);
 void mhi_write_reg(struct mhi_controller *mhi_cntrl, void __iomem *base,
 		   u32 offset, u32 val);
 int __must_check mhi_write_reg_field(struct mhi_controller *mhi_cntrl,
diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
index d6653cbcf9..abb561db9a 100644
--- a/drivers/bus/mhi/host/main.c
+++ b/drivers/bus/mhi/host/main.c
@@ -40,10 +40,11 @@ int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl,
 
 int __must_check mhi_poll_reg_field(struct mhi_controller *mhi_cntrl,
 				    void __iomem *base, u32 offset,
-				    u32 mask, u32 val, u32 delayus)
+				    u32 mask, u32 val, u32 delayus,
+				    u32 timeout_ms)
 {
 	int ret;
-	u32 out, retry = (mhi_cntrl->timeout_ms * 1000) / delayus;
+	u32 out, retry = (timeout_ms * 1000) / delayus;
 
 	while (retry--) {
 		ret = mhi_read_reg_field(mhi_cntrl, base, offset, mask, &out);
diff --git a/drivers/bus/mhi/host/pci_generic.c b/drivers/bus/mhi/host/pci_generic.c
index 08f3f039db..cd6cd14b3d 100644
--- a/drivers/bus/mhi/host/pci_generic.c
+++ b/drivers/bus/mhi/host/pci_generic.c
@@ -269,6 +269,16 @@ static struct mhi_event_config modem_qcom_v1_mhi_events[] = {
 	MHI_EVENT_CONFIG_HW_DATA(5, 2048, 101)
 };
 
+static const struct mhi_controller_config modem_qcom_v2_mhiv_config = {
+	.max_channels = 128,
+	.timeout_ms = 8000,
+	.ready_timeout_ms = 50000,
+	.num_channels = ARRAY_SIZE(modem_qcom_v1_mhi_channels),
+	.ch_cfg = modem_qcom_v1_mhi_channels,
+	.num_events = ARRAY_SIZE(modem_qcom_v1_mhi_events),
+	.event_cfg = modem_qcom_v1_mhi_events,
+};
+
 static const struct mhi_controller_config modem_qcom_v1_mhiv_config = {
 	.max_channels = 128,
 	.timeout_ms = 8000,
@@ -278,6 +288,16 @@ static const struct mhi_controller_config modem_qcom_v1_mhiv_config = {
 	.event_cfg = modem_qcom_v1_mhi_events,
 };
 
+static const struct mhi_pci_dev_info mhi_qcom_sdx75_info = {
+	.name = "qcom-sdx75m",
+	.fw = "qcom/sdx75m/xbl.elf",
+	.edl = "qcom/sdx75m/edl.mbn",
+	.config = &modem_qcom_v2_mhiv_config,
+	.bar_num = MHI_PCI_DEFAULT_BAR_NUM,
+	.dma_data_width = 32,
+	.sideband_wake = false,
+};
+
 static const struct mhi_pci_dev_info mhi_qcom_sdx65_info = {
 	.name = "qcom-sdx65m",
 	.fw = "qcom/sdx65m/xbl.elf",
@@ -600,6 +620,8 @@ static const struct pci_device_id mhi_pci_id_table[] = {
 		.driver_data = (kernel_ulong_t) &mhi_telit_fn990_info },
 	{ PCI_DEVICE(PCI_VENDOR_ID_QCOM, 0x0308),
 		.driver_data = (kernel_ulong_t) &mhi_qcom_sdx65_info },
+	{ PCI_DEVICE(PCI_VENDOR_ID_QCOM, 0x0309),
+		.driver_data = (kernel_ulong_t) &mhi_qcom_sdx75_info },
 	{ PCI_DEVICE(PCI_VENDOR_ID_QUECTEL, 0x1001), /* EM120R-GL (sdx24) */
 		.driver_data = (kernel_ulong_t) &mhi_quectel_em1xx_info },
 	{ PCI_DEVICE(PCI_VENDOR_ID_QUECTEL, 0x1002), /* EM160R-GL (sdx24) */
diff --git a/drivers/bus/mhi/host/pm.c b/drivers/bus/mhi/host/pm.c
index 8a4362d75f..d0d033ce99 100644
--- a/drivers/bus/mhi/host/pm.c
+++ b/drivers/bus/mhi/host/pm.c
@@ -36,7 +36,10 @@
  *     M0 <--> M0
  *     M0 -> FW_DL_ERR
  *     M0 -> M3_ENTER -> M3 -> M3_EXIT --> M0
- * L1: SYS_ERR_DETECT -> SYS_ERR_PROCESS --> POR
+ * L1: SYS_ERR_DETECT -> SYS_ERR_PROCESS
+ *     SYS_ERR_PROCESS -> SYS_ERR_FAIL
+ *     SYS_ERR_FAIL -> SYS_ERR_DETECT
+ *     SYS_ERR_PROCESS --> POR
  * L2: SHUTDOWN_PROCESS -> LD_ERR_FATAL_DETECT
  *     SHUTDOWN_PROCESS -> DISABLE
  * L3: LD_ERR_FATAL_DETECT <--> LD_ERR_FATAL_DETECT
@@ -93,7 +96,12 @@ static const struct mhi_pm_transitions dev_state_transitions[] = {
 	},
 	{
 		MHI_PM_SYS_ERR_PROCESS,
-		MHI_PM_POR | MHI_PM_SHUTDOWN_PROCESS |
+		MHI_PM_POR | MHI_PM_SYS_ERR_FAIL | MHI_PM_SHUTDOWN_PROCESS |
+		MHI_PM_LD_ERR_FATAL_DETECT
+	},
+	{
+		MHI_PM_SYS_ERR_FAIL,
+		MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
 		MHI_PM_LD_ERR_FATAL_DETECT
 	},
 	/* L2 States */
@@ -163,6 +171,7 @@ int mhi_ready_state_transition(struct mhi_controller *mhi_cntrl)
 	enum mhi_pm_state cur_state;
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
 	u32 interval_us = 25000; /* poll register field every 25 milliseconds */
+	u32 timeout_ms;
 	int ret, i;
 
 	/* Check if device entered error state */
@@ -173,14 +182,18 @@ int mhi_ready_state_transition(struct mhi_controller *mhi_cntrl)
 
 	/* Wait for RESET to be cleared and READY bit to be set by the device */
 	ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
-				 MHICTRL_RESET_MASK, 0, interval_us);
+				 MHICTRL_RESET_MASK, 0, interval_us,
+				 mhi_cntrl->timeout_ms);
 	if (ret) {
 		dev_err(dev, "Device failed to clear MHI Reset\n");
 		return ret;
 	}
 
+	timeout_ms = mhi_cntrl->ready_timeout_ms ?
+		mhi_cntrl->ready_timeout_ms : mhi_cntrl->timeout_ms;
 	ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHISTATUS,
-				 MHISTATUS_READY_MASK, 1, interval_us);
+				 MHISTATUS_READY_MASK, 1, interval_us,
+				 timeout_ms);
 	if (ret) {
 		dev_err(dev, "Device failed to enter MHI Ready\n");
 		return ret;
@@ -479,7 +492,7 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl)
 
 		/* Wait for the reset bit to be cleared by the device */
 		ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
-				 MHICTRL_RESET_MASK, 0, 25000);
+				 MHICTRL_RESET_MASK, 0, 25000, mhi_cntrl->timeout_ms);
 		if (ret)
 			dev_err(dev, "Device failed to clear MHI Reset\n");
 
@@ -492,8 +505,8 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl)
 		if (!MHI_IN_PBL(mhi_get_exec_env(mhi_cntrl))) {
 			/* wait for ready to be set */
 			ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs,
-						 MHISTATUS,
-						 MHISTATUS_READY_MASK, 1, 25000);
+						 MHISTATUS, MHISTATUS_READY_MASK,
+						 1, 25000, mhi_cntrl->timeout_ms);
 			if (ret)
 				dev_err(dev, "Device failed to enter READY state\n");
 		}
@@ -624,7 +637,13 @@ static void mhi_pm_sys_error_transition(struct mhi_controller *mhi_cntrl)
 					!in_reset, timeout);
 		if (!ret || in_reset) {
 			dev_err(dev, "Device failed to exit MHI Reset state\n");
-			goto exit_sys_error_transition;
+			write_lock_irq(&mhi_cntrl->pm_lock);
+			cur_state = mhi_tryset_pm_state(mhi_cntrl,
+							MHI_PM_SYS_ERR_FAIL);
+			write_unlock_irq(&mhi_cntrl->pm_lock);
+			/* Shutdown may have occurred, otherwise cleanup now */
+			if (cur_state != MHI_PM_SYS_ERR_FAIL)
+				goto exit_sys_error_transition;
 		}
 
 		/*
@@ -1111,7 +1130,8 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
 	if (state == MHI_STATE_SYS_ERR) {
 		mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET);
 		ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
-				 MHICTRL_RESET_MASK, 0, interval_us);
+				 MHICTRL_RESET_MASK, 0, interval_us,
+				 mhi_cntrl->timeout_ms);
 		if (ret) {
 			dev_info(dev, "Failed to reset MHI due to syserr state\n");
 			goto error_exit;
@@ -1202,14 +1222,18 @@ EXPORT_SYMBOL_GPL(mhi_power_down);
 int mhi_sync_power_up(struct mhi_controller *mhi_cntrl)
 {
 	int ret = mhi_async_power_up(mhi_cntrl);
+	u32 timeout_ms;
 
 	if (ret)
 		return ret;
 
+	/* Some devices need more time to set ready during power up */
+	timeout_ms = mhi_cntrl->ready_timeout_ms ?
+		mhi_cntrl->ready_timeout_ms : mhi_cntrl->timeout_ms;
 	wait_event_timeout(mhi_cntrl->state_event,
 			   MHI_IN_MISSION_MODE(mhi_cntrl->ee) ||
 			   MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
-			   msecs_to_jiffies(mhi_cntrl->timeout_ms));
+			   msecs_to_jiffies(timeout_ms));
 
 	ret = (MHI_IN_MISSION_MODE(mhi_cntrl->ee)) ? 0 : -ETIMEDOUT;
 	if (ret)