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Commit a8c77ef0 authored by Mayank Rana's avatar Mayank Rana
Browse files

usb: bam: Fix USB IPA BAM disconnect sequence 



Currently below mentioned USB IPA bam disconnect sequence is used:
1. USB bam driver disconnects IPA producer pipe.
2. USB bam driver releases IPA RM resource for USB_PROD and wait for
IPA producer to be released.
3. Here USB consumer is also being released.
4. USB bam driver before disconnects USB producer bam pipe, It is
waiting for USB producer bam pipe to be empty, and not finding empty,
it is trying to inject ZLT.

USB_PROD with IPA RM resource can't be released if USB driver wants
to make sure that data from USB bam produer pipe is drained out and
also wants to inject ZLT to signal the same. This results into
unclock access while injecting ZLT. Hence fix this issue by correcting
USB IPA bam disconnect sequence as below:
1. USB bam driver disconnects IPA Producer pipe.
2. USB bam driver before disconnects USB producer bam pipe, It is
waiting for USB producer BAM pipe to be empty, and not finding it,
it is trying to inject ZLT.
3. USB BAM driver releases IPA RM resource for USB_PROD and wait for
IPA producer to be release if above step 2 is completed.
4. Here USB consumer is also being released.

Change-Id: Iba04c9884ffc4a76ac98854eebd10f8955ce7141
Signed-off-by: default avatarMayank Rana <mrana@codeaurora.org>
parent 3c5189d0

drivers/platform/msm/usb_bam.c

+17 −28
Original line number Diff line number Diff line
@@ -844,8 +844,7 @@ static bool usb_bam_resume_core(enum usb_ctrl bam_type, 
 * usb_bam_disconnect_ipa_prod() - disconnects the USB consumer i.e. IPA producer.

 * @ipa_params: USB IPA related parameters

 * @cur_bam: USB controller used for BAM functionality

 * @bam_mode: USB controller based BAM used in Device or Host Mode



 *

 * It performs disconnect with IPA driver for IPA producer pipe and

 * with SPS driver for USB BAM consumer pipe. This API also takes care

 * of SYS2BAM and BAM2BAM IPA disconnect functionality.
@@ -854,42 +853,19 @@ static bool usb_bam_resume_core(enum usb_ctrl bam_type, 
 */

static int usb_bam_disconnect_ipa_prod(

		struct usb_bam_connect_ipa_params *ipa_params,

		enum usb_ctrl cur_bam, enum usb_bam_mode bam_mode)

		enum usb_ctrl cur_bam)

{

	int ret;

	u8 idx = 0;

	struct usb_bam_pipe_connect *pipe_connect;

	struct usb_bam_ctx_type *ctx = &msm_usb_bam[cur_bam];

	bool is_dpl;



	idx = ipa_params->dst_idx;

	/*

	 * Check for dpl client and if it is, then make adjustment

	 * to make decision about IPA Handshake.

	 */

	if (ipa_params->dst_client == IPA_CLIENT_USB_DPL_CONS)

		is_dpl = true;

	else

		is_dpl = false;



	pipe_connect = &ctx->usb_bam_connections[idx];



	pipe_connect->activity_notify = NULL;

	pipe_connect->inactivity_notify = NULL;

	pipe_connect->priv = NULL;



	/* Do the release handshake with the IPA via RM for non-DPL case*/

	spin_lock(&usb_bam_ipa_handshake_info_lock);

	if (bam_mode == USB_BAM_DEVICE && !is_dpl) {

		info[cur_bam].connect_complete = 0;

		info[cur_bam].disconnected = 1;

	}

	spin_unlock(&usb_bam_ipa_handshake_info_lock);



	/* Start release handshake on the last producer pipe for non-DPL case*/

	if (info[cur_bam].prod_pipes_enabled_per_bam == 1 && !is_dpl)

		wait_for_prod_release(cur_bam);



	/* close IPA -> USB pipe */

	if (pipe_connect->pipe_type == USB_BAM_PIPE_BAM2BAM) {

		ret = ipa_disconnect(ipa_params->prod_clnt_hdl);
@@ -979,6 +955,7 @@ retry: 
	if (!pipe_empty) {

		if (inject_zlt) {

			pr_debug("%s: Inject ZLT\n", __func__);

			log_event_dbg("%s: Inject ZLT\n", __func__);

			inject_zlt = false;

			sps_pipe_inject_zlt(sps_connection->destination,

					sps_connection->dest_pipe_index);
@@ -993,6 +970,16 @@ retry: 
		panic("%s:SPS pipe not empty for USB->IPA\n", __func__);

	}



	/* Do the release handshake with the IPA via RM */

	spin_lock(&usb_bam_ipa_handshake_info_lock);

	info[cur_bam].connect_complete = 0;

	info[cur_bam].disconnected = 1;

	spin_unlock(&usb_bam_ipa_handshake_info_lock);



	/* Start release handshake on the last USB BAM producer pipe */

	if (info[cur_bam].prod_pipes_enabled_per_bam == 1)

		wait_for_prod_release(cur_bam);



	/* close USB -> IPA pipe */

	if (pipe_connect->pipe_type == USB_BAM_PIPE_BAM2BAM) {

		ret = ipa_disconnect(ipa_params->cons_clnt_hdl);
@@ -2670,11 +2657,13 @@ int usb_bam_disconnect_ipa(enum usb_ctrl cur_bam, 
	pipe_connect = &ctx->usb_bam_connections[idx];

	bam_mode = pipe_connect->bam_mode;



	if (bam_mode != USB_BAM_DEVICE)

		return -EINVAL;



	mutex_lock(&info[cur_bam].suspend_resume_mutex);

	/* Delay USB core to go into lpm before we finish our handshake */

	if (is_ipa_handle_valid(ipa_params->prod_clnt_hdl)) {

		ret = usb_bam_disconnect_ipa_prod(ipa_params,

				cur_bam, bam_mode);

		ret = usb_bam_disconnect_ipa_prod(ipa_params, cur_bam);

		if (ret)

			goto out;

		pipes_disconncted++;