linux-kernel - Re: [PATCH v2 0/4] usb: typec: tipd: add patch update support for tps6598x

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Date: Thu, 4 Jan 2024 21:17:00 +0530
From: Jai Luthra <j-luthra@...com>
To: Javier Carrasco <javier.carrasco@...fvision.net>,
        Greg Kroah-Hartman
	<gregkh@...uxfoundation.org>
CC: Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        <linux-usb@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <vigneshr@...com>, <d-gole@...com>, <nm@...com>, <rogerq@...nel.org>
Subject: Re: [PATCH v2 0/4] usb: typec: tipd: add patch update support for
 tps6598x

Hi Javier,

On Jan 04, 2024 at 19:50:05 +0530, Jai Luthra wrote:
> Hi Javier, Greg,
> 
> On Dec 14, 2023 at 17:29:08 +0100, Javier Carrasco wrote:
> > This series extends the patch update mechanism to support the tps6598x.
> > 
> > Currently there is only support for the tps25750 part and some
> > conditional clauses are used to make a special case out of it. Now that
> > different parts support patch updates, a more general approach is
> > proposed.
> > 
> > The update mechanism differs from the one required by tps25750 and it is
> > explained in the commit message as a summary of the application note in
> > that respect.
> > 
> > Note that the series makes use of the TPS_SETUP_MS introduced in
> > commit 6a4d4a27f986 ("usb: typec: tps6598x: add reset gpio support"),
> > which is currently available in usb-next / usb-testing.
> > 
> > A TPS65987D has been used to test this functionality with positive
> > results.
> > 
> > Signed-off-by: Javier Carrasco <javier.carrasco@...fvision.net>
> > ---
> > Changes in v2:
> > - Remove probe defeferring mechanism and expect the firmware to be
> >   available (Heikki Krogerus).
> > - Link to v1: 
> > https://lore.kernel.org/r/20231207-tps6598x_update-v1-0-dc21b5301d91@wolfvision.net
> > 
> 
> FYI, this series breaks boot for TI SK-AM62A and SK-AM62 which use 
> TPS6598x as the USB-C PD chip.
> 
> The platforms stopped booting since next-20240103 [1], and reverting 
> this series [4] seems to fix the issue [2]
> 
> Is there any change needed in the board device-tree [3] and bindings?
> 
> We don't specify any firmware in the device-tree node, but seems like 
> that is an assumption in this series. I tried reverting it (below 
> change) but that did *not* help with the stuck boot.
> 
> diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
> index a956eb976906..fa3bd7349265 100644
> --- a/drivers/usb/typec/tipd/core.c
> +++ b/drivers/usb/typec/tipd/core.c
> @@ -1139,7 +1139,7 @@ static int tps6598x_apply_patch(struct tps6598x *tps)
>         ret = device_property_read_string(tps->dev, "firmware-name",
>                                           &firmware_name);
>         if (ret)
> -               return ret;
> +               return 0;
> 
>         ret = tps_request_firmware(tps, &fw);
>         if (ret)
> 
> 
> [1] https://linux.kernelci.org/soc/ti/job/next/kernel/next-20240103/plan/baseline-nfs/
> [2] https://gist.github.com/jailuthra/0c077176585e4df2f8b78f7784087865
> [3] https://gitlab.com/linux-kernel/linux-next/-/blob/master/arch/arm64/boot/dts/ti/k3-am62a7-sk.dts#L305
> [4] https://github.com/jailuthra/linux/commits/next-20240103-tps6598-fix/

The following change seems to fix boot on SK-AM62A without reverting 
this whole series:

------------------

diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
index a956eb976906a5..8ba2aa05db519b 100644
--- a/drivers/usb/typec/tipd/core.c
+++ b/drivers/usb/typec/tipd/core.c
@@ -1223,11 +1223,16 @@ static int cd321x_reset(struct tps6598x *tps)
 	return 0;
 }
 
-static int tps6598x_reset(struct tps6598x *tps)
+static int tps25750_reset(struct tps6598x *tps)
 {
 	return tps6598x_exec_cmd_tmo(tps, "GAID", 0, NULL, 0, NULL, 2000, 0);
 }
 
+static int tps6598x_reset(struct tps6598x *tps)
+{
+	return 0;
+}
+
 static int
 tps25750_register_port(struct tps6598x *tps, struct fwnode_handle *fwnode)
 {
@@ -1545,7 +1550,7 @@ static const struct tipd_data tps25750_data = {
 	.trace_status = trace_tps25750_status,
 	.apply_patch = tps25750_apply_patch,
 	.init = tps25750_init,
-	.reset = tps6598x_reset,
+	.reset = tps25750_reset,
 };
 
 static const struct of_device_id tps6598x_of_match[] = {

------------------

I am not an expert on this, will let you/others decide on what should be 
the correct way to reset TPS6598x for patching without breaking this SK.


-- 
Thanks,
Jai

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