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Message-ID: <Zs-PUNQI6SFWH6s_@google.com>
Date: Wed, 28 Aug 2024 13:57:52 -0700
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: Woody Suwalski <terraluna977@...il.com>
Cc: LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] mouse_cypress_ps2: Fix 6.11 regression on xps15z
On Wed, Aug 28, 2024 at 12:15:24PM -0700, Dmitry Torokhov wrote:
> On Tue, Aug 27, 2024 at 10:46:11PM -0400, Woody Suwalski wrote:
> > Dmitry Torokhov wrote:
> > > Hi Woody,
> > >
> > > On Tue, Aug 27, 2024 at 07:44:12PM -0400, Woody Suwalski wrote:
> > > > Kernel 6.11 rcN on Dell XPS 15Z: touch pad has stopped working after the
> > > > patch
> > > >
> > > > commit 8bccf667f62a2351fd0b2a2fe5ba90806702c048
> > > > Author: Dmitry Torokhov <dmitry.torokhov@...il.com>
> > > > Date: Fri Jun 28 15:47:25 2024 -0700
> > > >
> > > > Input: cypress_ps2 - report timeouts when reading command status
> > > >
> > > > It seems that the first communication is with an invalid packet of 3 NULLs,
> > > > and that
> > > > status failure used to be ignored. With the above patch it is now returning
> > > > an error and
> > > > that results in a dead touch pad.
> > > >
> > > > The fix is to stop flagging an error for 3-byte null packets, just keep
> > > > ignoring them as before.
> > > > [ 2.338016] [ T591] err: Command 0x00 response data (0x): 00 00 00
> > > > [ 2.338032] [ T591] ok: Command 0x00 response data (0x): 33 cc a2
> > > > ...
> > > > [ 2.770029] [ T591] ok: Command 0x00 response data (0x): 33 cc a2
> > > > [ 2.998030] [ T591] ok: Command 0x11 response data (0x): 01 00 64
> > > Could you please send me logs with i8042.debug=1 kernel command line
> > > option please? I wonder if we need to wake up the controller...
> > >
> > > Thanks.
> > >
> > Sure, the dmesg log is attached (for the failing scenario)
>
> Thank you.
>
> > [ 0.000000] [ T0] Linux version 6.9.0-pingu+ (root@...lXPS15Z) (gcc (Debian 14.2.0-1) 14.2.0, GNU ld (GNU Binutils for Debian) 2.43.1) #24 SMP PREEMPT_DYNAMIC Tue Aug 27 22:33:33 EDT 2024
>
> This is not 6.11, did you patch 6.9 with cypress patches from 6.11?
>
> Anyway, the patch you posted does not make sense. You are doing the
> following check:
>
> + if (!(pktsize == 3 && param[0] == 0 && param[1] == 0 )) {
> + rc = -ETIMEDOUT;
> + goto out;
> + }
>
> trying to ignore "all zeroes" response from the device, however at this
> point param array does not contain data from the device, it always
> contains all zeroes because of memset() a few lines above. So in effect
> you always skipping reporting timeout.
>
> However I think cypress is busted in general as it looks like it times
> out all the commands, because it tries to issue them outside of libp2s,
> and so noone is actually wakes it up when we get enough response from
> the device. To prove this could you please try applying this:
>
> diff --git a/drivers/input/mouse/cypress_ps2.c b/drivers/input/mouse/cypress_ps2.c
> index b3c34ebcc4ef..8c0c7100aa4d 100644
> --- a/drivers/input/mouse/cypress_ps2.c
> +++ b/drivers/input/mouse/cypress_ps2.c
> @@ -115,8 +115,9 @@ static int cypress_ps2_read_cmd_status(struct psmouse *psmouse,
> if (!wait_event_timeout(ps2dev->wait,
> psmouse->pktcnt >= pktsize,
> msecs_to_jiffies(CYTP_CMD_TIMEOUT))) {
> - rc = -ETIMEDOUT;
> - goto out;
> +// rc = -ETIMEDOUT;
> +// goto out;
> + pr_err("XXX looks like timeout\n");
> }
>
> memcpy(param, psmouse->packet, pktsize);
>
> and let me know if you see "XXX looks like timeout" multiple times
> during initialization (essentially for each extended command issued by
> the cypress driver)?
>
> Thanks!
And I wonder if this fixes it properly:
diff --git a/drivers/input/mouse/cypress_ps2.c b/drivers/input/mouse/cypress_ps2.c
index b3c34ebcc4ef..9446657a5f35 100644
--- a/drivers/input/mouse/cypress_ps2.c
+++ b/drivers/input/mouse/cypress_ps2.c
@@ -91,48 +91,6 @@ static int cypress_ps2_ext_cmd(struct psmouse *psmouse, u8 prefix, u8 nibble)
return rc;
}
-static int cypress_ps2_read_cmd_status(struct psmouse *psmouse,
- u8 cmd, u8 *param)
-{
- struct ps2dev *ps2dev = &psmouse->ps2dev;
- enum psmouse_state old_state;
- int pktsize;
- int rc;
-
- ps2_begin_command(ps2dev);
-
- old_state = psmouse->state;
- psmouse->state = PSMOUSE_CMD_MODE;
- psmouse->pktcnt = 0;
-
- pktsize = (cmd == CYTP_CMD_READ_TP_METRICS) ? 8 : 3;
- memset(param, 0, pktsize);
-
- rc = cypress_ps2_sendbyte(psmouse, PSMOUSE_CMD_GETINFO & 0xff);
- if (rc)
- goto out;
-
- if (!wait_event_timeout(ps2dev->wait,
- psmouse->pktcnt >= pktsize,
- msecs_to_jiffies(CYTP_CMD_TIMEOUT))) {
- rc = -ETIMEDOUT;
- goto out;
- }
-
- memcpy(param, psmouse->packet, pktsize);
-
- psmouse_dbg(psmouse, "Command 0x%02x response data (0x): %*ph\n",
- cmd, pktsize, param);
-
-out:
- psmouse->state = old_state;
- psmouse->pktcnt = 0;
-
- ps2_end_command(ps2dev);
-
- return rc;
-}
-
static bool cypress_verify_cmd_state(struct psmouse *psmouse, u8 cmd, u8* param)
{
bool rate_match = false;
@@ -166,6 +124,8 @@ static bool cypress_verify_cmd_state(struct psmouse *psmouse, u8 cmd, u8* param)
static int cypress_send_ext_cmd(struct psmouse *psmouse, u8 cmd, u8 *param)
{
u8 cmd_prefix = PSMOUSE_CMD_SETRES & 0xff;
+ unsigned int resp_size = cmd == CYTP_CMD_READ_TP_METRICS ? 8 : 3;
+ unsigned int ps2_cmd = (PSMOUSE_CMD_GETINFO & 0xff) | (resp_size << 8);
int tries = CYTP_PS2_CMD_TRIES;
int error;
@@ -179,10 +139,18 @@ static int cypress_send_ext_cmd(struct psmouse *psmouse, u8 cmd, u8 *param)
cypress_ps2_ext_cmd(psmouse, cmd_prefix, DECODE_CMD_BB(cmd));
cypress_ps2_ext_cmd(psmouse, cmd_prefix, DECODE_CMD_AA(cmd));
- error = cypress_ps2_read_cmd_status(psmouse, cmd, param);
- if (!error && cypress_verify_cmd_state(psmouse, cmd, param))
- return 0;
+ error = ps2_command(&psmouse->ps2dev, param, ps2_cmd);
+ if (error) {
+ psmouse_dbg(psmouse, "Command 0x%02x failed: %d\n",
+ cmd, error);
+ } else {
+ psmouse_dbg(psmouse,
+ "Command 0x%02x response data (0x): %*ph\n",
+ cmd, resp_size, param);
+ if (cypress_verify_cmd_state(psmouse, cmd, param))
+ return 0;
+ }
} while (--tries > 0);
return -EIO;
Thanks.
--
Dmitry
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