Re: [PATCH v3] mailbox: imx: add support for imx v1 mu

[Daniel Baluta <daniel.baluta@gmail.com>]

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Hi Richard,

Thanks for the patch. Please always add linux-imx@nxp.com mailing
list for imx related patches. I missed it.

Few comments inline.

Please also update in a separate patch attached to this series
the devictree bindings doc Documentation/devicetree/bindings/mailbox/fsl,mu.txt
by adding description for mx7ulp-mu

<snip>

> There is a version1.0 MU on i.MX7ULP platform.

space between version and 1.0

> One new version ID register is added, and it's offset is 0.
> TRn registers are defined at the offset 0x20 ~ 0x2C.
> RRn registers are defined at the offset 0x40 ~ 0x4C.
> SR/CR registers are defined at 0x60/0x64.
> Extend this driver to support it.

Do you have a little bit of history about MU versioning? So there was:

* version 0.5 on i.MX6-es
* version 1.0 on i.MX7ULP

Next, is this 1.0 compatbile with i.MX8 right?

Also, can you please rebase your patch on my 2 bugfixes attached?

thanks,
Daniel.

[-- Attachment #2: 0002-mailbox-imx-Clear-the-right-interrupts-at-shutdown.patch --]
[-- Type: text/x-patch, Size: 1275 bytes --]

From f9f382b8cab2cf88abf7fb26b885ac96e0cbaff4 Mon Sep 17 00:00:00 2001
From: Daniel Baluta <daniel.baluta@nxp.com>
Date: Thu, 1 Aug 2019 17:41:25 +0300
Subject: [PATCH 2/2] mailbox: imx: Clear the right interrupts at shutdown

Make sure to only clear enabled interrupts keeping count
of the connection type.

Suggested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
---
 drivers/mailbox/imx-mailbox.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/mailbox/imx-mailbox.c b/drivers/mailbox/imx-mailbox.c
index 957c10c4e674..3ecebdc7f913 100644
--- a/drivers/mailbox/imx-mailbox.c
+++ b/drivers/mailbox/imx-mailbox.c
@@ -219,8 +219,19 @@ static void imx_mu_shutdown(struct mbox_chan *chan)
 		return;
 	}
 
-	imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_TIEn(cp->idx) |
-		       IMX_MU_xCR_RIEn(cp->idx) | IMX_MU_xCR_GIEn(cp->idx));
+	switch (cp->type) {
+		case IMX_MU_TYPE_TX:
+		imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_TIEn(cp->idx));
+		break;
+	case IMX_MU_TYPE_RX:
+		imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_RIEn(cp->idx));
+		break;
+	case IMX_MU_TYPE_RXDB:
+		imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_GIEn(cp->idx));
+		break;
+	default:
+		break;
+	}
 
 	free_irq(priv->irq, chan);
 }
-- 
2.17.1


[-- Attachment #3: 0001-mailbox-imx-Fix-Tx-doorbell-shutdown-path.patch --]
[-- Type: text/x-patch, Size: 2937 bytes --]

From 8c7670c9198336f5e83f8322cb94ba776b759125 Mon Sep 17 00:00:00 2001
From: Daniel Baluta <daniel.baluta@nxp.com>
Date: Wed, 31 Jul 2019 23:47:29 +0300
Subject: [PATCH 1/2] mailbox: imx: Fix Tx doorbell shutdown path

Tx doorbell is handled by txdb_tasklet and doesn't
have an associated IRQ.

Anyhow, imx_mu_shutdown ignores this and tries to
free an IRQ that wasn't requested for Tx DB resulting
in the following warning:

[    1.967644] Trying to free already-free IRQ 26
[    1.972108] WARNING: CPU: 2 PID: 157 at kernel/irq/manage.c:1708 __free_irq+0xc0/0x358
[    1.980024] Modules linked in:
[    1.983088] CPU: 2 PID: 157 Comm: kworker/2:1 Tainted: G
[    1.993524] Hardware name: Freescale i.MX8QXP MEK (DT)
[    1.998668] Workqueue: events deferred_probe_work_func
[    2.003812] pstate: 60000085 (nZCv daIf -PAN -UAO)
[    2.008607] pc : __free_irq+0xc0/0x358
[    2.012364] lr : __free_irq+0xc0/0x358
[    2.016111] sp : ffff00001179b7e0
[    2.019422] x29: ffff00001179b7e0 x28: 0000000000000018
[    2.024736] x27: ffff000011233000 x26: 0000000000000004
[    2.030053] x25: 000000000000001a x24: ffff80083bec74d4
[    2.035369] x23: 0000000000000000 x22: ffff80083bec7588
[    2.040686] x21: ffff80083b1fe8d8 x20: ffff80083bec7400
[    2.046003] x19: 0000000000000000 x18: ffffffffffffffff
[    2.051320] x17: 0000000000000000 x16: 0000000000000000
[    2.056637] x15: ffff0000111296c8 x14: ffff00009179b517
[    2.061953] x13: ffff00001179b525 x12: ffff000011142000
[    2.067270] x11: ffff000011129f20 x10: ffff0000105da970
[    2.072587] x9 : 00000000ffffffd0 x8 : 0000000000000194
[    2.077903] x7 : 612065657266206f x6 : ffff0000111e7b09
[    2.083220] x5 : 0000000000000003 x4 : 0000000000000000
[    2.088537] x3 : 0000000000000000 x2 : 00000000ffffffff
[    2.093854] x1 : 28b70f0a2b60a500 x0 : 0000000000000000
[    2.099173] Call trace:
[    2.101618]  __free_irq+0xc0/0x358
[    2.105021]  free_irq+0x38/0x98
[    2.108170]  imx_mu_shutdown+0x90/0xb0
[    2.111921]  mbox_free_channel.part.2+0x24/0xb8
[    2.116453]  mbox_free_channel+0x18/0x28

This bug is present from the beginning of times.

Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
---
 drivers/mailbox/imx-mailbox.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mailbox/imx-mailbox.c b/drivers/mailbox/imx-mailbox.c
index 9f74dee1a58c..957c10c4e674 100644
--- a/drivers/mailbox/imx-mailbox.c
+++ b/drivers/mailbox/imx-mailbox.c
@@ -214,8 +214,10 @@ static void imx_mu_shutdown(struct mbox_chan *chan)
 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
 	struct imx_mu_con_priv *cp = chan->con_priv;
 
-	if (cp->type == IMX_MU_TYPE_TXDB)
+	if (cp->type == IMX_MU_TYPE_TXDB) {
 		tasklet_kill(&cp->txdb_tasklet);
+		return;
+	}
 
 	imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_TIEn(cp->idx) |
 		       IMX_MU_xCR_RIEn(cp->idx) | IMX_MU_xCR_GIEn(cp->idx));
-- 
2.17.1