From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Zhao Subject: Re: [PATCH 3/4] i2c: imx: add macros and printk to make debug easy Date: Thu, 1 Oct 2009 17:30:48 +0800 Message-ID: <4e090d470910010230h387cdc88h94f33bee405e6165@mail.gmail.com> References: <1254359613-21210-1-git-send-email-linuxzsc@gmail.com> <1254359613-21210-2-git-send-email-linuxzsc@gmail.com> <1254359613-21210-3-git-send-email-linuxzsc@gmail.com> <20091001072934.GX27039@pengutronix.de> <4e090d470910010101r6839cc9ax4fe84f04a1afbb00@mail.gmail.com> <20091001082610.GB27039@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20091001082610.GB27039-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sascha Hauer Cc: kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org List-Id: linux-i2c@vger.kernel.org On Thu, Oct 1, 2009 at 4:26 PM, Sascha Hauer w= rote: > On Thu, Oct 01, 2009 at 04:01:50PM +0800, Richard Zhao wrote: >> On Thu, Oct 1, 2009 at 3:29 PM, Sascha Hauer wrote: >> > On Thu, Oct 01, 2009 at 09:13:32AM +0800, Richard Zhao wrote: >> >> When CONFIG_I2C_DEBUG_BUS is enabled, it helps dump registers at = operation >> >> fail condition, and print i2c_msg to xfer. >> >> >> >> Signed-off-by: Richard Zhao >> > >> > Honestly I don't think we need this. It makes the driver too verbo= se for >> > my taste. >> > >> > Sascha >> > >> > >> >> >> >> diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2= c-imx.c >> >> index c1e541c..87faea4 100644 >> >> --- a/drivers/i2c/busses/i2c-imx.c >> >> +++ b/drivers/i2c/busses/i2c-imx.c >> >> @@ -125,6 +125,20 @@ struct imx_i2c_struct { >> >> =A0/** Functions for IMX I2C adapter driver *********************= ****************** >> >> =A0**************************************************************= *****************/ >> >> >> >> +#ifdef CONFIG_I2C_DEBUG_BUS >> >> +#define reg_dump(i2c_imx) \ >> >> +{ \ >> >> + =A0 =A0 printk(KERN_DEBUG "fun %s:%d ", __func__, __LINE__); \ >> >> + =A0 =A0 printk(KERN_DEBUG "IADR %02x IFDR %02x I2CR %02x I2SR %= 02x\n", \ >> >> + =A0 =A0 =A0 =A0 =A0 =A0 readb(i2c_imx->base + IMX_I2C_IADR), \ >> >> + =A0 =A0 =A0 =A0 =A0 =A0 readb(i2c_imx->base + IMX_I2C_IFDR), \ >> >> + =A0 =A0 =A0 =A0 =A0 =A0 readb(i2c_imx->base + IMX_I2C_I2CR), \ >> >> + =A0 =A0 =A0 =A0 =A0 =A0 readb(i2c_imx->base + IMX_I2C_I2SR)); \ >> >> +} >> >> +#else >> >> +#define reg_dump(i2c_imx) >> >> +#endif >> >> + >> >> =A0static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, in= t for_busy) >> >> =A0{ >> >> =A0 =A0 =A0 unsigned long orig_jiffies =3D jiffies; >> >> @@ -146,6 +160,7 @@ static int i2c_imx_bus_busy(struct imx_i2c_st= ruct *i2c_imx, int for_busy) >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 if (time_after(jiffies, orig_jiffies = + HZ / 1000)) { >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 dev_dbg(&i2c_imx->ada= pter.dev, >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 "<%s>= I2C bus is busy\n", __func__); >> >> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 reg_dump(i2c_imx); >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 return -EIO; >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 } >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 schedule(); >> >> @@ -164,9 +179,11 @@ static int i2c_imx_trx_complete(struct imx_i= 2c_struct *i2c_imx) >> >> >> >> =A0 =A0 =A0 if (unlikely(result < 0)) { >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 dev_dbg(&i2c_imx->adapter.dev, "<%s> = result < 0\n", __func__); >> >> + =A0 =A0 =A0 =A0 =A0 =A0 reg_dump(i2c_imx); >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 return result; >> >> =A0 =A0 =A0 } else if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) { >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 dev_dbg(&i2c_imx->adapter.dev, "<%s> = Timeout\n", __func__); >> >> + =A0 =A0 =A0 =A0 =A0 =A0 reg_dump(i2c_imx); >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 return -ETIMEDOUT; >> >> =A0 =A0 =A0 } >> >> =A0 =A0 =A0 dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n",= __func__); >> >> @@ -178,6 +195,7 @@ static int i2c_imx_acked(struct imx_i2c_struc= t *i2c_imx) >> >> =A0{ >> >> =A0 =A0 =A0 if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) = { >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 dev_dbg(&i2c_imx->adapter.dev, "<%s> = No ACK\n", __func__); >> >> + =A0 =A0 =A0 =A0 =A0 =A0 reg_dump(i2c_imx); >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 return -EIO; =A0/* No ACK */ >> >> =A0 =A0 =A0 } >> >> >> >> @@ -197,17 +215,20 @@ static int i2c_imx_start(struct imx_i2c_str= uct *i2c_imx) >> >> =A0 =A0 =A0 writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR); >> >> >> >> =A0 =A0 =A0 result =3D i2c_imx_bus_busy(i2c_imx, 0); >> >> - =A0 =A0 if (result) >> >> + =A0 =A0 if (result) { >> >> + =A0 =A0 =A0 =A0 =A0 =A0 reg_dump(i2c_imx); >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 return result; >> >> + =A0 =A0 } >> >> >> >> =A0 =A0 =A0 /* Start I2C transaction */ >> >> =A0 =A0 =A0 temp =3D readb(i2c_imx->base + IMX_I2C_I2CR); >> >> =A0 =A0 =A0 temp |=3D I2CR_MSTA; >> >> =A0 =A0 =A0 writeb(temp, i2c_imx->base + IMX_I2C_I2CR); >> >> =A0 =A0 =A0 result =3D i2c_imx_bus_busy(i2c_imx, 1); >> >> - =A0 =A0 if (result) >> >> + =A0 =A0 if (result) { >> >> + =A0 =A0 =A0 =A0 =A0 =A0 reg_dump(i2c_imx); >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 return result; >> >> - >> >> + =A0 =A0 } >> >> =A0 =A0 =A0 temp |=3D I2CR_IIEN | I2CR_MTX | I2CR_TXAK; >> >> =A0 =A0 =A0 writeb(temp, i2c_imx->base + IMX_I2C_I2CR); >> >> =A0 =A0 =A0 return result; >> >> @@ -228,7 +249,8 @@ static void i2c_imx_stop(struct imx_i2c_struc= t *i2c_imx) >> >> =A0 =A0 =A0 =A0*/ >> >> =A0 =A0 =A0 udelay(i2c_imx->disable_delay); >> >> >> >> - =A0 =A0 i2c_imx_bus_busy(i2c_imx, 0); >> >> + =A0 =A0 if (i2c_imx_bus_busy(i2c_imx, 0)) >> >> + =A0 =A0 =A0 =A0 =A0 =A0 reg_dump(i2c_imx); >> >> >> >> =A0 =A0 =A0 /* Disable I2C controller */ >> >> =A0 =A0 =A0 writeb(0, i2c_imx->base + IMX_I2C_I2CR); >> >> @@ -389,7 +411,18 @@ static int i2c_imx_xfer(struct i2c_adapter *= adapter, >> >> =A0 =A0 =A0 struct imx_i2c_struct *i2c_imx =3D i2c_get_adapdata(a= dapter); >> >> >> >> =A0 =A0 =A0 dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__); >> >> - >> >> +#ifdef CONFIG_I2C_DEBUG_BUS >> >> + =A0 =A0 for (i =3D 0; i < num; i++) { >> >> + =A0 =A0 =A0 =A0 =A0 =A0 printk(KERN_DEBUG "msg%d addr %02x RD %= d cnt %d d:", i, >> >> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 msgs[i].addr, msgs[i].f= lags & I2C_M_RD, msgs[i].len); >> >> + =A0 =A0 =A0 =A0 =A0 =A0 if (!(msgs[i].flags & I2C_M_RD)) { >> >> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 int j; >> >> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 for (j =3D 0; j < msgs[= i].len; j++) >> >> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 printk(= "%02x ", msgs[i].buf[j]); >> >> + =A0 =A0 =A0 =A0 =A0 =A0 } >> >> + =A0 =A0 =A0 =A0 =A0 =A0 printk("\n"); >> >> + =A0 =A0 } >> >> +#endif >> >> =A0 =A0 =A0 /* Start I2C transfer */ >> >> =A0 =A0 =A0 result =3D i2c_imx_start(i2c_imx); >> >> =A0 =A0 =A0 if (result) >> >> @@ -404,8 +437,10 @@ static int i2c_imx_xfer(struct i2c_adapter *= adapter, >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 temp |=3D I2CR_RSTA; >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 writeb(temp, i2c_imx-= >base + IMX_I2C_I2CR); >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 result =3D =A0i2c_imx= _bus_busy(i2c_imx, 1); >> >> - =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 if (result) >> >> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 if (result) { >> >> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 reg_dum= p(i2c_imx); >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 goto = fail0; >> >> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 } >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 } >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 dev_dbg(&i2c_imx->adapter.dev, >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 "<%s> transfer messag= e: %d\n", __func__, i); >> >> @@ -562,7 +597,7 @@ static int __init i2c_imx_probe(struct platfo= rm_device *pdev) >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 res_size, i2c_imx->res->start); >> >> =A0 =A0 =A0 dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\= n", >> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 i2c_imx->adapter.name); >> >> - =A0 =A0 dev_dbg(&i2c_imx->adapter.dev, "IMX I2C adapter registe= red\n"); >> >> + =A0 =A0 dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter regist= ered\n"); >> >> >> >> =A0 =A0 =A0 return 0; =A0 /* Return OK */ >> >> >> >> -- >> >> 1.6.0.4 >> >> >> >> >> > >> > -- >> > Pengutronix e.K. =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0= | =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 | >> > Industrial Linux Solutions =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 | http:= //www.pengutronix.de/ =A0| >> > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-20691= 7-0 =A0 =A0| >> > Amtsgericht Hildesheim, HRA 2686 =A0 =A0 =A0 =A0 =A0 | Fax: =A0 +4= 9-5121-206917-5555 | >> > >> >> 1. i2c is more important bus in embedded system than PC. Many PMICs >> are connected to cpu via i2c. Before system boot up, we depend much = on >> printk message. >> 2. When we add a new i2c device, it's easy to have problems. Maybe >> it's hw issue, one device fails, all ones in the same bus fails. In >> such condition, debug message is very helpfull. > > The driver already consists to 15% of debug statements, there is > definitely no need to add even more. If anything, you could concentra= te > on making the output more useful. The dump_reg are only added when operation fails. It's not used to track function call path or anything else. I'm not supposed to show detailed message when there's operation fail? The reason to add a switch to disable it is, when i2c tools scan the bus, it will cause operation fail. Richard > > Sascha > > -- > Pengutronix e.K. =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 = | =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 | > Industrial Linux Solutions =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 | http://w= ww.pengutronix.de/ =A0| > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0= =A0 =A0| > Amtsgericht Hildesheim, HRA 2686 =A0 =A0 =A0 =A0 =A0 | Fax: =A0 +49-5= 121-206917-5555 | >