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From:   Oliver Graute <oliver.graute@gmail.com>
To:     dmitry.torokhov@gmail.com
Cc:     oliver.graute@gmail.com,
        Oliver Graute <oliver.graute@kococonnector.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Marco Felsch <m.felsch@pengutronix.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Sasha Levin <sashal@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v1] Input: edt-ft5x06 - fix crash on EDT EP0110M09
Date:   Thu,  9 Apr 2020 11:27:01 +0200
Message-Id: <1586424425-27038-1-git-send-email-oliver.graute@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Oliver Graute <oliver.graute@kococonnector.com>

remove edt_ft5x06_ts_readwrite() call because this result in a stack
corruption crash on EP011M09

[    2.968250] edt_ft5x06 1-0038: 1-0038 supply vcc not found, using dummy regulator
[    2.991327] input: EP0110M09 as /devices/platform/bus@5a000000/5a820000.i2c/i2c-1/1-0038/input/input0
[    3.011818] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: edt_ft5x06_ts_probe+0x9e4/0xa98
[    3.022519] CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.6.0-rc1-next-20200214+ #69
[    3.030261] Hardware name: Advantech iMX8QM DMSSE20 (DT)
[    3.035583] Workqueue: events deferred_probe_work_func
[    3.040724] Call trace:
[    3.043179]  dump_backtrace+0x0/0x1c0
[    3.046839]  show_stack+0x14/0x20
[    3.050161]  dump_stack+0xb4/0xfc
[    3.053477]  panic+0x158/0x320
[    3.056531]  print_tainted+0x0/0xa8
[    3.060015]  edt_ft5x06_ts_probe+0x9e4/0xa98
[    3.064286]  i2c_device_probe+0x2d0/0x2f8
[    3.068299]  really_probe+0xd8/0x438
[    3.071874]  driver_probe_device+0xdc/0x130
[    3.076064]  __device_attach_driver+0x88/0x108
[    3.080511]  bus_for_each_drv+0x74/0xc0
[    3.084349]  __device_attach+0xdc/0x160
[    3.088189]  device_initial_probe+0x10/0x18
[    3.092376]  bus_probe_device+0x90/0x98
[    3.096210]  device_add+0x434/0x770
[    3.099699]  device_register+0x1c/0x28
[    3.103447]  i2c_new_client_device+0x134/0x2a8
[    3.107897]  of_i2c_register_device+0xb0/0xd8
[    3.112253]  of_i2c_register_devices+0x9c/0x198
[    3.116780]  i2c_register_adapter+0x150/0x418
[    3.121141]  __i2c_add_numbered_adapter+0x58/0xa0
[    3.125849]  i2c_add_adapter+0x9c/0xc8
[    3.129598]  lpi2c_imx_probe+0x1b0/0x2a0
[    3.133523]  platform_drv_probe+0x50/0xa0
[    3.137534]  really_probe+0xd8/0x438
[    3.141105]  driver_probe_device+0xdc/0x130
[    3.145284]  __device_attach_driver+0x88/0x108
[    3.149731]  bus_for_each_drv+0x74/0xc0
[    3.153562]  __device_attach+0xdc/0x160
[    3.157394]  device_initial_probe+0x10/0x18
[    3.161581]  bus_probe_device+0x90/0x98
[    3.165412]  deferred_probe_work_func+0x88/0xd8
[    3.169942]  process_one_work+0x19c/0x320
[    3.173952]  worker_thread+0x1f0/0x420
[    3.177703]  kthread+0xf0/0x120
[    3.180843]  ret_from_fork+0x10/0x18
[    3.184432] SMP: stopping secondary CPUs
[    3.188362] Kernel Offset: disabled
[    3.191853] CPU features: 0x10002,2100600c
[    3.195951] Memory Limit: none

Signed-off-by: Oliver Graute <oliver.graute@kococonnector.com>
---
 drivers/input/touchscreen/edt-ft5x06.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
index 06aa8ba0b6d7..6fbc87d041a1 100644
--- a/drivers/input/touchscreen/edt-ft5x06.c
+++ b/drivers/input/touchscreen/edt-ft5x06.c
@@ -819,10 +819,6 @@ static int edt_ft5x06_ts_identify(struct i2c_client *client,
 	 * to have garbage in there
 	 */
 	memset(rdbuf, 0, sizeof(rdbuf));
-	error = edt_ft5x06_ts_readwrite(client, 1, "\xBB",
-					EDT_NAME_LEN - 1, rdbuf);
-	if (error)
-		return error;
 
 	/* Probe content for something consistent.
 	 * M06 starts with a response byte, M12 gives the data directly.
-- 
2.17.1