| Message ID | 20241125141521.1612947-1-carlos.song@nxp.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | i2c: imx: fix divide by zero warning | expand |
> -----Original Message----- > From: Frank Li <frank.li@nxp.com> > Sent: Tuesday, November 26, 2024 1:18 AM > To: Carlos Song <carlos.song@nxp.com> > Cc: o.rempel@pengutronix.de; kernel@pengutronix.de; andi.shyti@kernel.org; > shawnguo@kernel.org; s.hauer@pengutronix.de; festevam@gmail.com; > linux-i2c@vger.kernel.org; imx@lists.linux.dev; > linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org > Subject: Re: [PATCH] i2c: imx: fix divide by zero warning > > On Mon, Nov 25, 2024 at 10:15:21PM +0800, carlos.song@nxp.com wrote: > > From: Carlos Song <carlos.song@nxp.com> > > > > Add "i2c_clk_rate / 2" check to avoid "divide by zero warning". > > i2c_clk_rate may be zero if i2c clock is disabled. > > > > Signed-off-by: Carlos Song <carlos.song@nxp.com> > > Signed-off-by: Clark Wang <xiaoning.wang@nxp.com> > > Signed-off-by: Haibo Chen <haibo.chen@nxp.com> > > --- > > You sent this patch twice? > Yes, because I meet a net error, I send the patch out and wait for a half of hour, but I don't see the mail in the mail list, so I send it again, but another one come in after 1 hour.. You can dismiss the same one. > Reviewed-by: Frank Li <Frank.Li@nxp.com> > > > drivers/i2c/busses/i2c-imx.c | 23 +++++++++++++++++------ > > 1 file changed, 17 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/i2c/busses/i2c-imx.c > > b/drivers/i2c/busses/i2c-imx.c index 2c782cdc26bd..5ed4cb61e262 100644 > > --- a/drivers/i2c/busses/i2c-imx.c > > +++ b/drivers/i2c/busses/i2c-imx.c > > @@ -623,8 +623,8 @@ static int i2c_imx_acked(struct imx_i2c_struct > *i2c_imx) > > return 0; > > } > > > > -static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx, > > - unsigned int i2c_clk_rate) > > +static int i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx, > > + unsigned int i2c_clk_rate) > > { > > struct imx_i2c_clk_pair *i2c_clk_div = i2c_imx->hwdata->clk_div; > > unsigned int div; > > @@ -639,7 +639,11 @@ static void i2c_imx_set_clk(struct imx_i2c_struct > > *i2c_imx, > > > > /* Divider value calculation */ > > if (i2c_imx->cur_clk == i2c_clk_rate) > > - return; > > + return 0; > > + > > + /* Keep the denominator of the following program always NOT equal to 0. > */ > > + if (!(i2c_clk_rate / 2)) > > + return -EINVAL; > > > > i2c_imx->cur_clk = i2c_clk_rate; > > > > @@ -670,6 +674,8 @@ static void i2c_imx_set_clk(struct imx_i2c_struct > *i2c_imx, > > dev_dbg(&i2c_imx->adapter.dev, "IFDR[IC]=0x%x, REAL DIV=%d\n", > > i2c_clk_div[i].val, i2c_clk_div[i].div); #endif > > + > > + return 0; > > } > > > > static int i2c_imx_clk_notifier_call(struct notifier_block *nb, @@ > > -679,11 +685,12 @@ static int i2c_imx_clk_notifier_call(struct notifier_block > *nb, > > struct imx_i2c_struct *i2c_imx = container_of(nb, > > struct imx_i2c_struct, > > clk_change_nb); > > + int ret = 0; > > > > if (action & POST_RATE_CHANGE) > > - i2c_imx_set_clk(i2c_imx, ndata->new_rate); > > + ret = i2c_imx_set_clk(i2c_imx, ndata->new_rate); > > > > - return NOTIFY_OK; > > + return notifier_from_errno(ret); > > } > > > > static int i2c_imx_start(struct imx_i2c_struct *i2c_imx, bool atomic) > > @@ -1782,7 +1789,11 @@ static int i2c_imx_probe(struct platform_device > *pdev) > > i2c_imx->bitrate = pdata->bitrate; > > i2c_imx->clk_change_nb.notifier_call = i2c_imx_clk_notifier_call; > > clk_notifier_register(i2c_imx->clk, &i2c_imx->clk_change_nb); > > - i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk)); > > + ret = i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk)); > > + if (ret < 0) { > > + dev_err(&pdev->dev, "can't get I2C clock\n"); > > + goto clk_notifier_unregister; > > + } > > > > i2c_imx_reset_regs(i2c_imx); > > > > -- > > 2.34.1 > >
> > You sent this patch twice? > > > Yes, because I meet a net error, I send the patch out and wait for a > half of hour, but I don't see the mail in the mail list, so I send it > again, but another one come in after 1 hour.. You can dismiss the same > one. You can also check 'http://patchwork.ozlabs.org/project/linux-i2c/list/' to see if it made it to the list.
> -----Original Message----- > From: Wolfram Sang <wsa+renesas@sang-engineering.com> > Sent: Friday, November 29, 2024 9:55 AM > To: Carlos Song <carlos.song@nxp.com> > Cc: Frank Li <frank.li@nxp.com>; o.rempel@pengutronix.de; > kernel@pengutronix.de; andi.shyti@kernel.org; shawnguo@kernel.org; > s.hauer@pengutronix.de; festevam@gmail.com; linux-i2c@vger.kernel.org; > imx@lists.linux.dev; linux-arm-kernel@lists.infradead.org; > linux-kernel@vger.kernel.org > Subject: [EXT] Re: [PATCH] i2c: imx: fix divide by zero warning > > > > > You sent this patch twice? > > > > > Yes, because I meet a net error, I send the patch out and wait for a > > half of hour, but I don't see the mail in the mail list, so I send it > > again, but another one come in after 1 hour.. You can dismiss the same > > one. > > You can also check 'http://patchwork.ozlabs.org/project/linux-i2c/list/' > to see if it made it to the list. Thank you! I will check it when I meet issue next time:).
Hi Carlos, On Mon, Nov 25, 2024 at 10:15:21PM +0800, carlos.song@nxp.com wrote: > From: Carlos Song <carlos.song@nxp.com> > > Add "i2c_clk_rate / 2" check to avoid "divide by zero warning". > i2c_clk_rate may be zero if i2c clock is disabled. > > Signed-off-by: Carlos Song <carlos.song@nxp.com> > Signed-off-by: Clark Wang <xiaoning.wang@nxp.com> > Signed-off-by: Haibo Chen <haibo.chen@nxp.com> merged to i2c/i2c-host, thanks, Andi
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 2c782cdc26bd..5ed4cb61e262 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -623,8 +623,8 @@ static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx) return 0; } -static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx, - unsigned int i2c_clk_rate) +static int i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx, + unsigned int i2c_clk_rate) { struct imx_i2c_clk_pair *i2c_clk_div = i2c_imx->hwdata->clk_div; unsigned int div; @@ -639,7 +639,11 @@ static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx, /* Divider value calculation */ if (i2c_imx->cur_clk == i2c_clk_rate) - return; + return 0; + + /* Keep the denominator of the following program always NOT equal to 0. */ + if (!(i2c_clk_rate / 2)) + return -EINVAL; i2c_imx->cur_clk = i2c_clk_rate; @@ -670,6 +674,8 @@ static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx, dev_dbg(&i2c_imx->adapter.dev, "IFDR[IC]=0x%x, REAL DIV=%d\n", i2c_clk_div[i].val, i2c_clk_div[i].div); #endif + + return 0; } static int i2c_imx_clk_notifier_call(struct notifier_block *nb, @@ -679,11 +685,12 @@ static int i2c_imx_clk_notifier_call(struct notifier_block *nb, struct imx_i2c_struct *i2c_imx = container_of(nb, struct imx_i2c_struct, clk_change_nb); + int ret = 0; if (action & POST_RATE_CHANGE) - i2c_imx_set_clk(i2c_imx, ndata->new_rate); + ret = i2c_imx_set_clk(i2c_imx, ndata->new_rate); - return NOTIFY_OK; + return notifier_from_errno(ret); } static int i2c_imx_start(struct imx_i2c_struct *i2c_imx, bool atomic) @@ -1782,7 +1789,11 @@ static int i2c_imx_probe(struct platform_device *pdev) i2c_imx->bitrate = pdata->bitrate; i2c_imx->clk_change_nb.notifier_call = i2c_imx_clk_notifier_call; clk_notifier_register(i2c_imx->clk, &i2c_imx->clk_change_nb); - i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk)); + ret = i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk)); + if (ret < 0) { + dev_err(&pdev->dev, "can't get I2C clock\n"); + goto clk_notifier_unregister; + } i2c_imx_reset_regs(i2c_imx);