LinuxLists.cc - [PATCH] i3c: update dw-i3c-master i3c_clk

2023-02-13 14:23:59

Subject: [PATCH] i3c: update dw-i3c-master i3c_clk_cfg function

Bus-speed could be default(12.5MHz) or defined by users in dts.
Dw-i3c-master should not hard-code the initial speed to be
I3C_BUS_TYP_I3C_SCL_RATE (12.5MHz)
And because of Synopsys's I3C controller limit (hcnt/lcnt register
length) and core-clk provided, there is a limit to bus speed, too.
For example, when core-clk is 250 MHz, the bus speed cannot be
lowered below 1MHz.

Tested: tested with an i3c sensor and captured with a logic analyzer.

Signed-off-by: Jack Chen <[email protected]>
---
drivers/i3c/master/dw-i3c-master.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
index 51a8608203de..13309dde1518 100644
--- a/drivers/i3c/master/dw-i3c-master.c
+++ b/drivers/i3c/master/dw-i3c-master.c
@@ -531,7 +531,7 @@ static int dw_i3c_clk_cfg(struct dw_i3c_master *master)
if (hcnt < SCL_I3C_TIMING_CNT_MIN)
hcnt = SCL_I3C_TIMING_CNT_MIN;

- lcnt = DIV_ROUND_UP(core_rate, I3C_BUS_TYP_I3C_SCL_RATE) - hcnt;
+ lcnt = DIV_ROUND_UP(core_rate, master->base.bus.scl_rate.i3c) - hcnt;
if (lcnt < SCL_I3C_TIMING_CNT_MIN)
lcnt = SCL_I3C_TIMING_CNT_MIN;

@@ -541,7 +541,7 @@ static int dw_i3c_clk_cfg(struct dw_i3c_master *master)
if (!(readl(master->regs + DEVICE_CTRL) & DEV_CTRL_I2C_SLAVE_PRESENT))
writel(BUS_I3C_MST_FREE(lcnt), master->regs + BUS_FREE_TIMING);

- lcnt = DIV_ROUND_UP(I3C_BUS_TLOW_OD_MIN_NS, core_period);
+ lcnt = max(DIV_ROUND_UP(I3C_BUS_TLOW_OD_MIN_NS, core_period), lcnt);
scl_timing = SCL_I3C_TIMING_HCNT(hcnt) | SCL_I3C_TIMING_LCNT(lcnt);
writel(scl_timing, master->regs + SCL_I3C_OD_TIMING);

--
2.39.1.581.gbfd45094c4-goog

2023-02-13 20:17:42

by kernel test robot

[permalink] [raw]

Subject: Re: [PATCH] i3c: update dw-i3c-master i3c_clk_cfg function

Hi Jack,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v6.2-rc8 next-20230213]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Jack-Chen/i3c-update-dw-i3c-master-i3c_clk_cfg-function/20230213-222533
patch link: https://lore.kernel.org/r/20230213142336.192875-1-zenghuchen%40google.com
patch subject: [PATCH] i3c: update dw-i3c-master i3c_clk_cfg function
config: hexagon-randconfig-r041-20230213 (https://download.01.org/0day-ci/archive/20230214/[email protected]/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project db89896bbbd2251fff457699635acbbedeead27f)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/e85b41ae5bb17077ac7d01bdd13c48ea1f83ea42
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Jack-Chen/i3c-update-dw-i3c-master-i3c_clk_cfg-function/20230213-222533
git checkout e85b41ae5bb17077ac7d01bdd13c48ea1f83ea42
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash drivers/i3c/master/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <[email protected]>
| Link: https://lore.kernel.org/oe-kbuild-all/[email protected]/

All warnings (new ones prefixed by >>):

In file included from drivers/i3c/master/dw-i3c-master.c:13:
In file included from include/linux/i3c/master.h:14:
In file included from include/linux/i2c.h:19:
In file included from include/linux/regulator/consumer.h:35:
In file included from include/linux/suspend.h:5:
In file included from include/linux/swap.h:9:
In file included from include/linux/memcontrol.h:13:
In file included from include/linux/cgroup.h:26:
In file included from include/linux/kernel_stat.h:9:
In file included from include/linux/interrupt.h:11:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/hexagon/include/asm/io.h:334:
include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __raw_readb(PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
#define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
^
In file included from drivers/i3c/master/dw-i3c-master.c:13:
In file included from include/linux/i3c/master.h:14:
In file included from include/linux/i2c.h:19:
In file included from include/linux/regulator/consumer.h:35:
In file included from include/linux/suspend.h:5:
In file included from include/linux/swap.h:9:
In file included from include/linux/memcontrol.h:13:
In file included from include/linux/cgroup.h:26:
In file included from include/linux/kernel_stat.h:9:
In file included from include/linux/interrupt.h:11:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/hexagon/include/asm/io.h:334:
include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
In file included from drivers/i3c/master/dw-i3c-master.c:13:
In file included from include/linux/i3c/master.h:14:
In file included from include/linux/i2c.h:19:
In file included from include/linux/regulator/consumer.h:35:
In file included from include/linux/suspend.h:5:
In file included from include/linux/swap.h:9:
In file included from include/linux/memcontrol.h:13:
In file included from include/linux/cgroup.h:26:
In file included from include/linux/kernel_stat.h:9:
In file included from include/linux/interrupt.h:11:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/hexagon/include/asm/io.h:334:
include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
>> drivers/i3c/master/dw-i3c-master.c:544:9: warning: comparison of distinct pointer types ('typeof ((((200) + (core_period) - 1) / (core_period))) *' (aka 'unsigned long *') and 'typeof (lcnt) *' (aka 'unsigned char *')) [-Wcompare-distinct-pointer-types]
lcnt = max(DIV_ROUND_UP(I3C_BUS_TLOW_OD_MIN_NS, core_period), lcnt);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:74:19: note: expanded from macro 'max'
#define max(x, y) __careful_cmp(x, y, >)
^~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:36:24: note: expanded from macro '__careful_cmp'
__builtin_choose_expr(__safe_cmp(x, y), \
^~~~~~~~~~~~~~~~
include/linux/minmax.h:26:4: note: expanded from macro '__safe_cmp'
(__typecheck(x, y) && __no_side_effects(x, y))
^~~~~~~~~~~~~~~~~
include/linux/minmax.h:20:28: note: expanded from macro '__typecheck'
(!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~
7 warnings generated.

vim +544 drivers/i3c/master/dw-i3c-master.c

517
518 static int dw_i3c_clk_cfg(struct dw_i3c_master *master)
519 {
520 unsigned long core_rate, core_period;
521 u32 scl_timing;
522 u8 hcnt, lcnt;
523
524 core_rate = clk_get_rate(master->core_clk);
525 if (!core_rate)
526 return -EINVAL;
527
528 core_period = DIV_ROUND_UP(1000000000, core_rate);
529
530 hcnt = DIV_ROUND_UP(I3C_BUS_THIGH_MAX_NS, core_period) - 1;
531 if (hcnt < SCL_I3C_TIMING_CNT_MIN)
532 hcnt = SCL_I3C_TIMING_CNT_MIN;
533
534 lcnt = DIV_ROUND_UP(core_rate, master->base.bus.scl_rate.i3c) - hcnt;
535 if (lcnt < SCL_I3C_TIMING_CNT_MIN)
536 lcnt = SCL_I3C_TIMING_CNT_MIN;
537
538 scl_timing = SCL_I3C_TIMING_HCNT(hcnt) | SCL_I3C_TIMING_LCNT(lcnt);
539 writel(scl_timing, master->regs + SCL_I3C_PP_TIMING);
540
541 if (!(readl(master->regs + DEVICE_CTRL) & DEV_CTRL_I2C_SLAVE_PRESENT))
542 writel(BUS_I3C_MST_FREE(lcnt), master->regs + BUS_FREE_TIMING);
543
> 544 lcnt = max(DIV_ROUND_UP(I3C_BUS_TLOW_OD_MIN_NS, core_period), lcnt);
545 scl_timing = SCL_I3C_TIMING_HCNT(hcnt) | SCL_I3C_TIMING_LCNT(lcnt);
546 writel(scl_timing, master->regs + SCL_I3C_OD_TIMING);
547
548 lcnt = DIV_ROUND_UP(core_rate, I3C_BUS_SDR1_SCL_RATE) - hcnt;
549 scl_timing = SCL_EXT_LCNT_1(lcnt);
550 lcnt = DIV_ROUND_UP(core_rate, I3C_BUS_SDR2_SCL_RATE) - hcnt;
551 scl_timing |= SCL_EXT_LCNT_2(lcnt);
552 lcnt = DIV_ROUND_UP(core_rate, I3C_BUS_SDR3_SCL_RATE) - hcnt;
553 scl_timing |= SCL_EXT_LCNT_3(lcnt);
554 lcnt = DIV_ROUND_UP(core_rate, I3C_BUS_SDR4_SCL_RATE) - hcnt;
555 scl_timing |= SCL_EXT_LCNT_4(lcnt);
556 writel(scl_timing, master->regs + SCL_EXT_LCNT_TIMING);
557
558 return 0;
559 }
560

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests

2023-02-14 02:13:02

by kernel test robot

[permalink] [raw]

Subject: Re: [PATCH] i3c: update dw-i3c-master i3c_clk_cfg function

2023-02-14 20:24:01

by Jack Chen

[permalink] [raw]

Subject: Re: [PATCH] i3c: update dw-i3c-master i3c_clk_cfg function

Thanks Intel kernel test robot.
I have submitted the V2 patch, which replaced max with max_t to do a type cast.

On Mon, Feb 13, 2023 at 9:13 PM kernel test robot <[email protected]> wrote:
>
> Hi Jack,
>
> Thank you for the patch! Perhaps something to improve:
>
> [auto build test WARNING on linus/master]
> [also build test WARNING on v6.2-rc8 next-20230213]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Jack-Chen/i3c-update-dw-i3c-master-i3c_clk_cfg-function/20230213-222533
> patch link: https://lore.kernel.org/r/20230213142336.192875-1-zenghuchen%40google.com
> patch subject: [PATCH] i3c: update dw-i3c-master i3c_clk_cfg function
> config: i386-randconfig-s001 (https://download.01.org/0day-ci/archive/20230214/[email protected]/config)
> compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
> reproduce:
> # apt-get install sparse
> # sparse version: v0.6.4-39-gce1a6720-dirty
> # https://github.com/intel-lab-lkp/linux/commit/e85b41ae5bb17077ac7d01bdd13c48ea1f83ea42
> git remote add linux-review https://github.com/intel-lab-lkp/linux
> git fetch --no-tags linux-review Jack-Chen/i3c-update-dw-i3c-master-i3c_clk_cfg-function/20230213-222533
> git checkout e85b41ae5bb17077ac7d01bdd13c48ea1f83ea42
> # save the config file
> mkdir build_dir && cp config build_dir/.config
> make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 olddefconfig
> make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 SHELL=/bin/bash drivers/i3c/master/
>
> If you fix the issue, kindly add following tag where applicable
> | Reported-by: kernel test robot <[email protected]>
> | Link: https://lore.kernel.org/oe-kbuild-all/[email protected]/
>
> sparse warnings: (new ones prefixed by >>)
> >> drivers/i3c/master/dw-i3c-master.c:544:16: sparse: sparse: incompatible types in comparison expression (different type sizes):
> >> drivers/i3c/master/dw-i3c-master.c:544:16: sparse: unsigned long *
> >> drivers/i3c/master/dw-i3c-master.c:544:16: sparse: unsigned char *
>
> vim +544 drivers/i3c/master/dw-i3c-master.c
>
> 517
> 518 static int dw_i3c_clk_cfg(struct dw_i3c_master *master)
> 519 {
> 520 unsigned long core_rate, core_period;
> 521 u32 scl_timing;
> 522 u8 hcnt, lcnt;
> 523
> 524 core_rate = clk_get_rate(master->core_clk);
> 525 if (!core_rate)
> 526 return -EINVAL;
> 527
> 528 core_period = DIV_ROUND_UP(1000000000, core_rate);
> 529
> 530 hcnt = DIV_ROUND_UP(I3C_BUS_THIGH_MAX_NS, core_period) - 1;
> 531 if (hcnt < SCL_I3C_TIMING_CNT_MIN)
> 532 hcnt = SCL_I3C_TIMING_CNT_MIN;
> 533
> 534 lcnt = DIV_ROUND_UP(core_rate, master->base.bus.scl_rate.i3c) - hcnt;
> 535 if (lcnt < SCL_I3C_TIMING_CNT_MIN)
> 536 lcnt = SCL_I3C_TIMING_CNT_MIN;
> 537
> 538 scl_timing = SCL_I3C_TIMING_HCNT(hcnt) | SCL_I3C_TIMING_LCNT(lcnt);
> 539 writel(scl_timing, master->regs + SCL_I3C_PP_TIMING);
> 540
> 541 if (!(readl(master->regs + DEVICE_CTRL) & DEV_CTRL_I2C_SLAVE_PRESENT))
> 542 writel(BUS_I3C_MST_FREE(lcnt), master->regs + BUS_FREE_TIMING);
> 543
> > 544 lcnt = max(DIV_ROUND_UP(I3C_BUS_TLOW_OD_MIN_NS, core_period), lcnt);
> 545 scl_timing = SCL_I3C_TIMING_HCNT(hcnt) | SCL_I3C_TIMING_LCNT(lcnt);
> 546 writel(scl_timing, master->regs + SCL_I3C_OD_TIMING);
> 547
> 548 lcnt = DIV_ROUND_UP(core_rate, I3C_BUS_SDR1_SCL_RATE) - hcnt;
> 549 scl_timing = SCL_EXT_LCNT_1(lcnt);
> 550 lcnt = DIV_ROUND_UP(core_rate, I3C_BUS_SDR2_SCL_RATE) - hcnt;
> 551 scl_timing |= SCL_EXT_LCNT_2(lcnt);
> 552 lcnt = DIV_ROUND_UP(core_rate, I3C_BUS_SDR3_SCL_RATE) - hcnt;
> 553 scl_timing |= SCL_EXT_LCNT_3(lcnt);
> 554 lcnt = DIV_ROUND_UP(core_rate, I3C_BUS_SDR4_SCL_RATE) - hcnt;
> 555 scl_timing |= SCL_EXT_LCNT_4(lcnt);
> 556 writel(scl_timing, master->regs + SCL_EXT_LCNT_TIMING);
> 557
> 558 return 0;
> 559 }
> 560
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests

2023-02-14 21:25:04

by Jack Chen

[permalink] [raw]

Subject: Re: Re: [PATCH] i3c: update dw-i3c-master i3c_clk_cfg function

Thanks Intel kernel test robot. This patch was meant for i3c tree.
And I have submitted a new V2 patch which replaced max with max_t to do the type cast.