Commit 11361456 authored by Alex Elder's avatar Alex Elder Committed by Jakub Kicinski
Browse files

net: ipa: support retries on generic GSI commands 



When stopping an AP RX channel, there can be a transient period
while the channel enters STOP_IN_PROC state before reaching the
final STOPPED state.  In that case we make another attempt to stop
the channel.

Similarly, when stopping a modem channel (using a GSI generic
command issued from the AP), it's possible that multiple attempts
will be required before the channel reaches STOPPED state.

Add a field to the GSI structure to record an errno representing the
result code provided when a generic command completes.  If the
result learned in gsi_isr_gp_int1() is RETRY, record -EAGAIN in the
result code, otherwise record 0 for success, or -EIO for any other
result.

If we time out nf gsi_generic_command() waiting for the command to
complete, return -ETIMEDOUT (as before).  Otherwise return the
result stashed by gsi_isr_gp_int1().

Add a loop in gsi_modem_channel_halt() to reissue the HALT command
if the result code indicates -EAGAIN.  Limit this to 10 retries
(after the initial attempt).

Signed-off-by: default avatarAlex Elder <elder@linaro.org>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent f849afcc

drivers/net/ipa/gsi.c

+19 −2
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 */
@@ -1107,10 +1108,16 @@ static void gsi_isr_gp_int1(struct gsi *gsi) 
	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;

	}
@@ -1624,7 +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);
@@ -1640,7 +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 */

};