| Message ID | 20161023102213.GA13705@amd (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sunday 23 October 2016 12:22:13 Pavel Machek wrote: > Hi! > > I tried to update camera code on n900 to v4.9-rc1, and I'm getting > some divide by zero, that eventually cascades into fcam-dev not > working. > > mul is zero in my testing, resulting in divide by zero. > > (Note that this is going from my patched camera-v4.8 tree to > camera-v4.9 tree.) > > Best regards, > Pavel Hi! Ideally look at existing camera patches. I do not know which one is last, but here are some links: https://github.com/freemangordon/linux-n900/tree/v4.6-rc4-n900-camera https://github.com/freemangordon/linux-n900/tree/camera https://git.kernel.org/cgit/linux/kernel/git/sre/linux-n900.git/log/?h=n900-camera-ivo https://git.kernel.org/cgit/linux/kernel/git/sre/linux-n900.git/log/?h=n900-camera > diff --git a/drivers/media/i2c/smiapp-pll.c > b/drivers/media/i2c/smiapp-pll.c index 5ad1edb..e0a6edd 100644 > --- a/drivers/media/i2c/smiapp-pll.c > +++ b/drivers/media/i2c/smiapp-pll.c > @@ -16,6 +16,8 @@ > * General Public License for more details. > */ > > +#define DEBUG > + > #include <linux/device.h> > #include <linux/gcd.h> > #include <linux/lcm.h> > @@ -457,6 +459,10 @@ int smiapp_pll_calculate(struct device *dev, > i = gcd(pll->pll_op_clk_freq_hz, pll->ext_clk_freq_hz); > mul = div_u64(pll->pll_op_clk_freq_hz, i); > div = pll->ext_clk_freq_hz / i; > + if (!mul) { > + dev_err(dev, "forcing mul to 1\n"); > + mul = 1; > + } > dev_dbg(dev, "mul %u / div %u\n", mul, div); > > min_pre_pll_clk_div = Is not this patch still enough? https://patchwork.kernel.org/patch/8921761/
Hi! > I tried to update camera code on n900 to v4.9-rc1, and I'm getting > some divide by zero, that eventually cascades into fcam-dev not > working. > > mul is zero in my testing, resulting in divide by zero. > > (Note that this is going from my patched camera-v4.8 tree to > camera-v4.9 tree.) If I revert the smiapp changes to the ones in camera-v4.8, I get fcam back, and can get pictures using the main camera. There are only few patches between v4.8 and v4.8 in smiapp, so I'll try to find what is going on there. Best regards, Pavel
Hi Pavel, On Sun, Oct 23, 2016 at 12:22:13PM +0200, Pavel Machek wrote: > Hi! > > I tried to update camera code on n900 to v4.9-rc1, and I'm getting > some divide by zero, that eventually cascades into fcam-dev not > working. > > mul is zero in my testing, resulting in divide by zero. > > (Note that this is going from my patched camera-v4.8 tree to > camera-v4.9 tree.) > > Best regards, > Pavel > > diff --git a/drivers/media/i2c/smiapp-pll.c b/drivers/media/i2c/smiapp-pll.c > index 5ad1edb..e0a6edd 100644 > --- a/drivers/media/i2c/smiapp-pll.c > +++ b/drivers/media/i2c/smiapp-pll.c > @@ -16,6 +16,8 @@ > * General Public License for more details. > */ > > +#define DEBUG > + > #include <linux/device.h> > #include <linux/gcd.h> > #include <linux/lcm.h> > @@ -457,6 +459,10 @@ int smiapp_pll_calculate(struct device *dev, > i = gcd(pll->pll_op_clk_freq_hz, pll->ext_clk_freq_hz); > mul = div_u64(pll->pll_op_clk_freq_hz, i); > div = pll->ext_clk_freq_hz / i; > + if (!mul) { Something must be very wrong if you get here. What are the values of pll->pll_op_clk_freq_hz and pll->ext_clk_freq_hz? Or... what does dmesg say? > + dev_err(dev, "forcing mul to 1\n"); > + mul = 1; > + } > dev_dbg(dev, "mul %u / div %u\n", mul, div); > > min_pre_pll_clk_div = >
Hi! > > +#define DEBUG > > + > > #include <linux/device.h> > > #include <linux/gcd.h> > > #include <linux/lcm.h> > > @@ -457,6 +459,10 @@ int smiapp_pll_calculate(struct device *dev, > > i = gcd(pll->pll_op_clk_freq_hz, pll->ext_clk_freq_hz); > > mul = div_u64(pll->pll_op_clk_freq_hz, i); > > div = pll->ext_clk_freq_hz / i; > > + if (!mul) { > > Something must be very wrong if you get here. > > What are the values of pll->pll_op_clk_freq_hz and pll->ext_clk_freq_hz? > Or... what does dmesg say? Yep, it was very wrong. I mismerged the stuff, and hwcfg->lanes initialization was missing. Now it appears to work. (I have pushed the changes to camera-v4.9 branch). Best regards, Pavel
diff --git a/drivers/media/i2c/smiapp-pll.c b/drivers/media/i2c/smiapp-pll.c index 5ad1edb..e0a6edd 100644 --- a/drivers/media/i2c/smiapp-pll.c +++ b/drivers/media/i2c/smiapp-pll.c @@ -16,6 +16,8 @@ * General Public License for more details. */ +#define DEBUG + #include <linux/device.h> #include <linux/gcd.h> #include <linux/lcm.h> @@ -457,6 +459,10 @@ int smiapp_pll_calculate(struct device *dev, i = gcd(pll->pll_op_clk_freq_hz, pll->ext_clk_freq_hz); mul = div_u64(pll->pll_op_clk_freq_hz, i); div = pll->ext_clk_freq_hz / i; + if (!mul) { + dev_err(dev, "forcing mul to 1\n"); + mul = 1; + } dev_dbg(dev, "mul %u / div %u\n", mul, div); min_pre_pll_clk_div =