From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: Re: [PATCH 3/3] TSC-40: Improve EEPROM error handling
Date: Tue, 13 Sep 2011 10:50:32 +0200
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To: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: linux-input@vger.kernel.org

* Christian Gmeiner | 2011-09-13 10:18:41 [+0200]:

>diff --git a/drivers/input/touchscreen/tsc40.c
>b/drivers/input/touchscreen/tsc40.c
>index b73ef2f..d914522 100644
>--- a/drivers/input/touchscreen/tsc40.c
>+++ b/drivers/input/touchscreen/tsc40.c
>@@ -49,7 +49,6 @@ struct tsc_ser {
>
> #define RESPONSE_ACK   0x06
>#define RESPONSE_NAK    0x15
>-#define NACK_DETAIL_NT (1 << 3)
>
> #define ID_EPROM_UNUSED        (1 << 7)
>
>@@ -96,11 +95,25 @@ static void handle_reset(struct serio *serio,
>unsigned char data)
>
>       /* NAK + EEPROM available */
>       if (ptsc->idx == 1) {
>-               if (!(data & NACK_DETAIL_NT)) {
>+               if (data & (1 << 0)) {
>+                       dev_warn(&serio->dev, "EEPROM data empty\n");
>+                       state_after_reset(ptsc, 1);
>+                       return;
>+               } else if (data & (1 << 1)) {
>+                       dev_warn(&serio->dev, "EEPROM data abnormal\n");
>                       state_after_reset(ptsc, 0);
>                       return;
>-               }
>-               state_after_reset(ptsc, 0);
>+               } else if (data & (1 << 2)) {
>+                       dev_warn(&serio->dev, "EEPROM write error\n");
>+                       state_after_reset(ptsc, 0);
>+                       return;
>+               } else if (data & (1 << 3)) {
>+                       dev_warn(&serio->dev, "Touch screen not connected\n");
>+                       state_after_reset(ptsc, 0);
>+                       return;
>+               } else
>+                       BUG_ON(1);
>+

That BUG() isn't really nice. Since you in probe at this time, couldn't
you print something and abort loading the driver?

Sebastian