Commit c9003783 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'net-ipa-add-a-driver-shutdown-callback' 

Alex Elder says:

====================
net: ipa: add a driver shutdown callback

The final patch in this series adds a driver shutdown callback for
the IPA driver.  The patches leading up to that address some issues
encountered while ensuring that callback worked as expected:
  - The first just reports a little more information when channels
    or event rings are in unexpected states
  - The second patch recognizes a condition where an as-yet-unused
    channel does not require a reset during teardown
  - The third patch explicitly ignores a certain error condition,
    because it can't be avoided, and is harmless if it occurs
  - The fourth properly handles requests to retry a channel HALT
    request
  - The fifth makes a second attempt to stop modem activity during
    shutdown if it's busy

The shutdown callback is implemented by calling the existing remove
callback function (reporting if that returns an error).
====================

Link: https://lore.kernel.org/r/20201119224929.23819-1-elder@linaro.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 0ee6de26 ae1d72f9

drivers/net/ipa/gsi.c

+76 −25
Original line number Diff line number Diff line
@@ -92,6 +92,7 @@ 
#define GSI_CMD_TIMEOUT			5	/* seconds */



#define GSI_CHANNEL_STOP_RX_RETRIES	10

#define GSI_CHANNEL_MODEM_HALT_RETRIES	10



#define GSI_MHI_EVENT_ID_START		10	/* 1st reserved event id */

#define GSI_MHI_EVENT_ID_END		16	/* Last reserved event id */
@@ -365,15 +366,15 @@ static int gsi_evt_ring_alloc_command(struct gsi *gsi, u32 evt_ring_id) 
	/* Get initial event ring state */

	evt_ring->state = gsi_evt_ring_state(gsi, evt_ring_id);

	if (evt_ring->state != GSI_EVT_RING_STATE_NOT_ALLOCATED) {

		dev_err(gsi->dev, "bad event ring state %u before alloc\n",

			evt_ring->state);

		dev_err(gsi->dev, "event ring %u bad state %u before alloc\n",

			evt_ring_id, evt_ring->state);

		return -EINVAL;

	}



	ret = evt_ring_command(gsi, evt_ring_id, GSI_EVT_ALLOCATE);

	if (!ret && evt_ring->state != GSI_EVT_RING_STATE_ALLOCATED) {

		dev_err(gsi->dev, "bad event ring state %u after alloc\n",

			evt_ring->state);

		dev_err(gsi->dev, "event ring %u bad state %u after alloc\n",

			evt_ring_id, evt_ring->state);

		ret = -EIO;

	}
@@ -389,15 +390,15 @@ static void gsi_evt_ring_reset_command(struct gsi *gsi, u32 evt_ring_id) 


	if (state != GSI_EVT_RING_STATE_ALLOCATED &&

	    state != GSI_EVT_RING_STATE_ERROR) {

		dev_err(gsi->dev, "bad event ring state %u before reset\n",

			evt_ring->state);

		dev_err(gsi->dev, "event ring %u bad state %u before reset\n",

			evt_ring_id, evt_ring->state);

		return;

	}



	ret = evt_ring_command(gsi, evt_ring_id, GSI_EVT_RESET);

	if (!ret && evt_ring->state != GSI_EVT_RING_STATE_ALLOCATED)

		dev_err(gsi->dev, "bad event ring state %u after reset\n",

			evt_ring->state);

		dev_err(gsi->dev, "event ring %u bad state %u after reset\n",

			evt_ring_id, evt_ring->state);

}



/* Issue a hardware de-allocation request for an allocated event ring */
@@ -407,15 +408,15 @@ static void gsi_evt_ring_de_alloc_command(struct gsi *gsi, u32 evt_ring_id) 
	int ret;



	if (evt_ring->state != GSI_EVT_RING_STATE_ALLOCATED) {

		dev_err(gsi->dev, "bad event ring state %u before dealloc\n",

			evt_ring->state);

		dev_err(gsi->dev, "event ring %u state %u before dealloc\n",

			evt_ring_id, evt_ring->state);

		return;

	}



	ret = evt_ring_command(gsi, evt_ring_id, GSI_EVT_DE_ALLOC);

	if (!ret && evt_ring->state != GSI_EVT_RING_STATE_NOT_ALLOCATED)

		dev_err(gsi->dev, "bad event ring state %u after dealloc\n",

			evt_ring->state);

		dev_err(gsi->dev, "event ring %u bad state %u after dealloc\n",

			evt_ring_id, evt_ring->state);

}



/* Fetch the current state of a channel from hardware */
@@ -479,7 +480,8 @@ static int gsi_channel_alloc_command(struct gsi *gsi, u32 channel_id) 
	/* Get initial channel state */

	state = gsi_channel_state(channel);

	if (state != GSI_CHANNEL_STATE_NOT_ALLOCATED) {

		dev_err(dev, "bad channel state %u before alloc\n", state);

		dev_err(dev, "channel %u bad state %u before alloc\n",

			channel_id, state);

		return -EINVAL;

	}
@@ -488,7 +490,8 @@ static int gsi_channel_alloc_command(struct gsi *gsi, u32 channel_id) 
	/* Channel state will normally have been updated */

	state = gsi_channel_state(channel);

	if (!ret && state != GSI_CHANNEL_STATE_ALLOCATED) {

		dev_err(dev, "bad channel state %u after alloc\n", state);

		dev_err(dev, "channel %u bad state %u after alloc\n",

			channel_id, state);

		ret = -EIO;

	}
@@ -505,7 +508,8 @@ static int gsi_channel_start_command(struct gsi_channel *channel) 
	state = gsi_channel_state(channel);

	if (state != GSI_CHANNEL_STATE_ALLOCATED &&

	    state != GSI_CHANNEL_STATE_STOPPED) {

		dev_err(dev, "bad channel state %u before start\n", state);

		dev_err(dev, "channel %u bad state %u before start\n",

			gsi_channel_id(channel), state);

		return -EINVAL;

	}
@@ -514,7 +518,8 @@ static int gsi_channel_start_command(struct gsi_channel *channel) 
	/* Channel state will normally have been updated */

	state = gsi_channel_state(channel);

	if (!ret && state != GSI_CHANNEL_STATE_STARTED) {

		dev_err(dev, "bad channel state %u after start\n", state);

		dev_err(dev, "channel %u bad state %u after start\n",

			gsi_channel_id(channel), state);

		ret = -EIO;

	}
@@ -538,7 +543,8 @@ static int gsi_channel_stop_command(struct gsi_channel *channel) 


	if (state != GSI_CHANNEL_STATE_STARTED &&

	    state != GSI_CHANNEL_STATE_STOP_IN_PROC) {

		dev_err(dev, "bad channel state %u before stop\n", state);

		dev_err(dev, "channel %u bad state %u before stop\n",

			gsi_channel_id(channel), state);

		return -EINVAL;

	}
@@ -553,7 +559,8 @@ static int gsi_channel_stop_command(struct gsi_channel *channel) 
	if (state == GSI_CHANNEL_STATE_STOP_IN_PROC)

		return -EAGAIN;



	dev_err(dev, "bad channel state %u after stop\n", state);

	dev_err(dev, "channel %u bad state %u after stop\n",

		gsi_channel_id(channel), state);



	return -EIO;

}
@@ -570,7 +577,10 @@ static void gsi_channel_reset_command(struct gsi_channel *channel) 
	state = gsi_channel_state(channel);

	if (state != GSI_CHANNEL_STATE_STOPPED &&

	    state != GSI_CHANNEL_STATE_ERROR) {

		dev_err(dev, "bad channel state %u before reset\n", state);

		/* No need to reset a channel already in ALLOCATED state */

		if (state != GSI_CHANNEL_STATE_ALLOCATED)

			dev_err(dev, "channel %u bad state %u before reset\n",

				gsi_channel_id(channel), state);

		return;

	}
@@ -579,7 +589,8 @@ static void gsi_channel_reset_command(struct gsi_channel *channel) 
	/* Channel state will normally have been updated */

	state = gsi_channel_state(channel);

	if (!ret && state != GSI_CHANNEL_STATE_ALLOCATED)

		dev_err(dev, "bad channel state %u after reset\n", state);

		dev_err(dev, "channel %u bad state %u after reset\n",

			gsi_channel_id(channel), state);

}



/* Deallocate an ALLOCATED GSI channel */
@@ -592,7 +603,8 @@ static void gsi_channel_de_alloc_command(struct gsi *gsi, u32 channel_id) 


	state = gsi_channel_state(channel);

	if (state != GSI_CHANNEL_STATE_ALLOCATED) {

		dev_err(dev, "bad channel state %u before dealloc\n", state);

		dev_err(dev, "channel %u bad state %u before dealloc\n",

			channel_id, state);

		return;

	}
@@ -601,7 +613,8 @@ static void gsi_channel_de_alloc_command(struct gsi *gsi, u32 channel_id) 
	/* Channel state will normally have been updated */

	state = gsi_channel_state(channel);

	if (!ret && state != GSI_CHANNEL_STATE_NOT_ALLOCATED)

		dev_err(dev, "bad channel state %u after dealloc\n", state);

		dev_err(dev, "channel %u bad state %u after dealloc\n",

			channel_id, state);

}



/* Ring an event ring doorbell, reporting the last entry processed by the AP.
@@ -1075,10 +1088,38 @@ static void gsi_isr_gp_int1(struct gsi *gsi) 
	u32 result;

	u32 val;



	/* This interrupt is used to handle completions of the two GENERIC

	 * GSI commands.  We use these to allocate and halt channels on

	 * the modem's behalf due to a hardware quirk on IPA v4.2.  Once

	 * allocated, the modem "owns" these channels, and as a result we

	 * have no way of knowing the channel's state at any given time.

	 *

	 * It is recommended that we halt the modem channels we allocated

	 * when shutting down, but it's possible the channel isn't running

	 * at the time we issue the HALT command.  We'll get an error in

	 * that case, but it's harmless (the channel is already halted).

	 *

	 * For this reason, we silently ignore a CHANNEL_NOT_RUNNING error

	 * if we receive it.

	 */

	val = ioread32(gsi->virt + GSI_CNTXT_SCRATCH_0_OFFSET);

	result = u32_get_bits(val, GENERIC_EE_RESULT_FMASK);

	if (result != GENERIC_EE_SUCCESS)



	switch (result) {

	case GENERIC_EE_SUCCESS:

	case GENERIC_EE_CHANNEL_NOT_RUNNING:

		gsi->result = 0;

		break;



	case GENERIC_EE_RETRY:

		gsi->result = -EAGAIN;

		break;



	default:

		dev_err(gsi->dev, "global INT1 generic result %u\n", result);

		gsi->result = -EIO;

		break;

	}



	complete(&gsi->completion);

}
@@ -1590,7 +1631,7 @@ static int gsi_generic_command(struct gsi *gsi, u32 channel_id, 
	iowrite32(BIT(ERROR_INT), gsi->virt + GSI_CNTXT_GLOB_IRQ_EN_OFFSET);



	if (success)

		return 0;

		return gsi->result;



	dev_err(gsi->dev, "GSI generic command %u to channel %u timed out\n",

		opcode, channel_id);
@@ -1606,7 +1647,17 @@ static int gsi_modem_channel_alloc(struct gsi *gsi, u32 channel_id) 


static void gsi_modem_channel_halt(struct gsi *gsi, u32 channel_id)

{

	(void)gsi_generic_command(gsi, channel_id, GSI_GENERIC_HALT_CHANNEL);

	u32 retries = GSI_CHANNEL_MODEM_HALT_RETRIES;

	int ret;



	do

		ret = gsi_generic_command(gsi, channel_id,

					  GSI_GENERIC_HALT_CHANNEL);

	while (ret == -EAGAIN && retries--);



	if (ret)

		dev_err(gsi->dev, "error %d halting modem channel %u\n",

			ret, channel_id);

}



/* Setup function for channels */

drivers/net/ipa/gsi.h

+1 −0
Original line number Diff line number Diff line
@@ -161,6 +161,7 @@ struct gsi { 
	u32 type_enabled_bitmap;	/* GSI IRQ types enabled */

	u32 ieob_enabled_bitmap;	/* IEOB IRQ enabled (event rings) */

	struct completion completion;	/* for global EE commands */

	int result;			/* Negative errno (generic commands) */

	struct mutex mutex;		/* protects commands, programming */

};

drivers/net/ipa/ipa_main.c

+17 −2
Original line number Diff line number Diff line
@@ -863,6 +863,11 @@ static int ipa_remove(struct platform_device *pdev) 


	if (ipa->setup_complete) {

		ret = ipa_modem_stop(ipa);

		/* If starting or stopping is in progress, try once more */

		if (ret == -EBUSY) {

			usleep_range(USEC_PER_MSEC, 2 * USEC_PER_MSEC);

			ret = ipa_modem_stop(ipa);

		}

		if (ret)

			return ret;
@@ -883,6 +888,15 @@ static int ipa_remove(struct platform_device *pdev) 
	return 0;

}



static void ipa_shutdown(struct platform_device *pdev)

{

	int ret;



	ret = ipa_remove(pdev);

	if (ret)

		dev_err(&pdev->dev, "shutdown: remove returned %d\n", ret);

}



/**

 * ipa_suspend() - Power management system suspend callback

 * @dev:	IPA device structure
@@ -942,6 +956,7 @@ static const struct dev_pm_ops ipa_pm_ops = { 
static struct platform_driver ipa_driver = {

	.probe		= ipa_probe,

	.remove		= ipa_remove,

	.shutdown	= ipa_shutdown,

	.driver	= {

		.name		= "ipa",

		.pm		= &ipa_pm_ops,

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