Revert "bus: mhi: Add inbound buffers allocation flag"

This reverts commit 0092a1e

This should be reverted in the char-misc-next branch to make merging
with Linus's branch possible due to issues with the mhi code that was
found in the networking tree.

Link: https://lore.kernel.org/r/20210827175852.GB15018@thinkpad
Reported-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bhaumik Bhatt <bbhatt@codeaurora.org>
Cc: Hemant Kumar <hemantk@codeaurora.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Loic Poulain <loic.poulain@linaro.org>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/bus/mhi/core/internal.h

@@ -682,7 +682,7 @@ void mhi_rddm_prepare(struct mhi_controller *mhi_cntrl,
 		      struct image_info *img_info);
 void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl);
 int mhi_prepare_channel(struct mhi_controller *mhi_cntrl,
-			struct mhi_chan *mhi_chan, unsigned int flags);
+			struct mhi_chan *mhi_chan);
 int mhi_init_chan_ctxt(struct mhi_controller *mhi_cntrl,
 		       struct mhi_chan *mhi_chan);
 void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,

drivers/bus/mhi/core/main.c

@@ -1430,7 +1430,7 @@ static void mhi_unprepare_channel(struct mhi_controller *mhi_cntrl,
 }
 
 int mhi_prepare_channel(struct mhi_controller *mhi_cntrl,
-			struct mhi_chan *mhi_chan, unsigned int flags)
+			struct mhi_chan *mhi_chan)
 {
 	int ret = 0;
 	struct device *dev = &mhi_chan->mhi_dev->dev;
@@ -1455,9 +1455,6 @@ int mhi_prepare_channel(struct mhi_controller *mhi_cntrl,
 	if (ret)
 		goto error_pm_state;
 
-	if (mhi_chan->dir == DMA_FROM_DEVICE)
-		mhi_chan->pre_alloc = !!(flags & MHI_CH_INBOUND_ALLOC_BUFS);
-
 	/* Pre-allocate buffer for xfer ring */
 	if (mhi_chan->pre_alloc) {
 		int nr_el = get_nr_avail_ring_elements(mhi_cntrl,
@@ -1613,7 +1610,7 @@ void mhi_reset_chan(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan)
 }
 
 /* Move channel to start state */
-int mhi_prepare_for_transfer(struct mhi_device *mhi_dev, unsigned int flags)
+int mhi_prepare_for_transfer(struct mhi_device *mhi_dev)
 {
 	int ret, dir;
 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
@@ -1624,7 +1621,7 @@ int mhi_prepare_for_transfer(struct mhi_device *mhi_dev, unsigned int flags)
 		if (!mhi_chan)
 			continue;
 
-		ret = mhi_prepare_channel(mhi_cntrl, mhi_chan, flags);
+		ret = mhi_prepare_channel(mhi_cntrl, mhi_chan);
 		if (ret)
 			goto error_open_chan;
 	}

drivers/net/mhi/net.c

@@ -335,7 +335,7 @@ static int mhi_net_newlink(void *ctxt, struct net_device *ndev, u32 if_id,
 	u64_stats_init(&mhi_netdev->stats.tx_syncp);
 
 	/* Start MHI channels */
-	err = mhi_prepare_for_transfer(mhi_dev, 0);
+	err = mhi_prepare_for_transfer(mhi_dev);
 	if (err)
 		goto out_err;
 

drivers/net/wwan/mhi_wwan_ctrl.c

@@ -110,7 +110,7 @@ static int mhi_wwan_ctrl_start(struct wwan_port *port)
 	int ret;
 
 	/* Start mhi device's channel(s) */
-	ret = mhi_prepare_for_transfer(mhiwwan->mhi_dev, 0);
+	ret = mhi_prepare_for_transfer(mhiwwan->mhi_dev);
 	if (ret)
 		return ret;
 

include/linux/mhi.h

@@ -721,13 +721,8 @@ void mhi_device_put(struct mhi_device *mhi_dev);
  *                            host and device execution environments match and
  *                            channels are in a DISABLED state.
  * @mhi_dev: Device associated with the channels
- * @flags: MHI channel flags
  */
-int mhi_prepare_for_transfer(struct mhi_device *mhi_dev,
-			     unsigned int flags);
-
-/* Automatically allocate and queue inbound buffers */
-#define MHI_CH_INBOUND_ALLOC_BUFS BIT(0)
+int mhi_prepare_for_transfer(struct mhi_device *mhi_dev);
 
 /**
  * mhi_unprepare_from_transfer - Reset UL and DL channels for data transfer.

net/qrtr/mhi.c

@@ -84,7 +84,7 @@ static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev,
 	int rc;
 
 	/* start channels */
-	rc = mhi_prepare_for_transfer(mhi_dev, MHI_CH_INBOUND_ALLOC_BUFS);
+	rc = mhi_prepare_for_transfer(mhi_dev);
 	if (rc)
 		return rc;