From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Denk Date: Mon, 12 Jan 2009 20:13:49 +0100 Subject: [U-Boot] Watchdog and u-boot command prompt In-Reply-To: <73FA539107892C4C8C7A5ACA10C161C85BE0E3@MX2.AlphionCorp.local> References: <73FA539107892C4C8C7A5ACA10C161C85BE0E3@MX2.AlphionCorp.local> Message-ID: <20090112191349.D2A2E832E425@gemini.denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Dear Sachin, In message <73FA539107892C4C8C7A5ACA10C161C85BE0E3@MX2.AlphionCorp.local> you wrote: > > I have enabled 'watchdog' in u-boot using flag 'CONFIG_WATCHDOG'. > I wonder how the 'watchdog' gets reset when the cursor is waiting for > user input. > > As per my understanding the 'WATCHDOG_RESET()' gets called in > 'readline()' prior calling 'getc()'. > In our case, the 'getc()' has been mapped to 'serial_getc_dev()' of > 'cpu/ppc4xx/serial.c'. There is no such file in U-Boot. > The code of 'serial_getc_dev()' executes in continous loop till user > presses a key. > The good thing is that the boad doesn't get reboot even if user doesn't > enter any key. > In 'serial_getc_dev()', I don't see any call to reset the watchdog . Hmmm... I don't know where you are looking. You say this is on ppc4xx, so I check "cpu/ppc4xx/4xx_uart.c" - and what do I see? 480 int serial_getc_dev (unsigned long base) 481 { 482 unsigned char status = 0; 483 484 while (1) { 485 #if defined(CONFIG_HW_WATCHDOG) 486 WATCHDOG_RESET (); /* Reset HW Watchdog, if needed */ 487 #endif /* CONFIG_HW_WATCHDOG */ 488 489 status = in_8((u8 *)base + UART_LSR); ... Looks pretty much as if it was an explicit call to trigger the watchdog... > Can you help me to find out the how Watchdog is taken care (gets reset) > whicle executing a infinite loop (if user doesn't press any key) ? > ( Note: I am not using 'CONFIG_HW_WATCHDOG' flag) You are not? Hmmm... What makes you think you are using a watchdog then? Which sort of watchdog device is used on your board? Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de I don't want to be young again, I just don't want to get any older.