| Message ID | MN2PR01MB535838492432C910F2381F929F6F9@MN2PR01MB5358.prod.exchangelabs.com |
|---|---|
| State | New |
| Headers | show |
| Series | i2c: pasemi: Add IRQ support for Apple Silicon | expand |
Hi Arminder,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on powerpc/next]
[also build test WARNING on linus/master v6.0-rc1 next-20220819]
[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/Arminder-Singh/i2c-pasemi-Add-IRQ-support-for-Apple-Silicon/20220821-034703
base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: riscv-randconfig-r042-20220821 (https://download.01.org/0day-ci/archive/20220821/202208210548.MCoIwyQl-lkp@intel.com/config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project c9a41fe60ab62f7a40049c100adcc8087a47669b)
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
# install riscv cross compiling tool for clang build
# apt-get install binutils-riscv64-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/98584b2b51d808ab582798c7a50511e8c1889ced
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Arminder-Singh/i2c-pasemi-Add-IRQ-support-for-Apple-Silicon/20220821-034703
git checkout 98584b2b51d808ab582798c7a50511e8c1889ced
# 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=riscv SHELL=/bin/bash drivers/i2c/busses/
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
In file included from drivers/i2c/busses/i2c-pasemi-core.c:9:
In file included from include/linux/pci.h:38:
In file included from include/linux/interrupt.h:11:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/riscv/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/riscv/include/asm/io.h:136:
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/i2c/busses/i2c-pasemi-core.c:9:
In file included from include/linux/pci.h:38:
In file included from include/linux/interrupt.h:11:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/riscv/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/riscv/include/asm/io.h:136:
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/i2c/busses/i2c-pasemi-core.c:9:
In file included from include/linux/pci.h:38:
In file included from include/linux/interrupt.h:11:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/riscv/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/riscv/include/asm/io.h:136:
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);
~~~~~~~~~~ ^
include/asm-generic/io.h:1134:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
~~~~~~~~~~ ^
>> drivers/i2c/busses/i2c-pasemi-core.c:86:6: warning: variable 'status' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
if (smbus->use_irq) {
^~~~~~~~~~~~~~
drivers/i2c/busses/i2c-pasemi-core.c:92:12: note: uninitialized use occurs here
while (!(status & SMSTA_XEN) && timeout--) {
^~~~~~
drivers/i2c/busses/i2c-pasemi-core.c:86:2: note: remove the 'if' if its condition is always true
if (smbus->use_irq) {
^~~~~~~~~~~~~~~~~~~~
drivers/i2c/busses/i2c-pasemi-core.c:83:21: note: initialize the variable 'status' to silence this warning
unsigned int status;
^
= 0
8 warnings generated.
vim +86 drivers/i2c/busses/i2c-pasemi-core.c
79
80 static int pasemi_smb_waitready(struct pasemi_smbus *smbus)
81 {
82 int timeout = 10;
83 unsigned int status;
84 unsigned int bitmask = SMSTA_XEN | SMSTA_MTN;
85
> 86 if (smbus->use_irq) {
87 reinit_completion(&smbus->irq_completion);
88 reg_write(smbus, REG_IMASK, bitmask);
89 wait_for_completion_timeout(&smbus->irq_completion, msecs_to_jiffies(10));
90 status = reg_read(smbus, REG_SMSTA);
91 } else {
92 while (!(status & SMSTA_XEN) && timeout--) {
93 msleep(1);
94 status = reg_read(smbus, REG_SMSTA);
95 }
96 }
97
98
99 /* Got NACK? */
100 if (status & SMSTA_MTN)
101 return -ENXIO;
102
103 if (timeout < 0) {
104 dev_warn(smbus->dev, "Timeout, status 0x%08x\n", status);
105 reg_write(smbus, REG_SMSTA, status);
106 return -ETIME;
107 }
108
109 /* Clear XEN */
110 reg_write(smbus, REG_SMSTA, SMSTA_XEN);
111
112 return 0;
113 }
114
On 23 August 2022 at 03:50 am, Michael Ellerman wrote: > Arminder Singh <arminders208@outlook.com> writes: >> This is the first time I'm interacting with the Linux mailing lists, so >> please don't eviscerate me *too much* if I get the formatting wrong. >> Of course I'm always willing to take criticism and improve my formatting >> in the future. >> >> This patch adds support for IRQs to the PASemi I2C controller driver. >> This will allow for faster performing I2C transactions on Apple Silicon >> hardware, as previously, the driver was forced to poll the SMSTA register >> for a set amount of time. >> >> With this patchset the driver on Apple silicon hardware will instead wait >> for an interrupt which will signal the completion of the I2C transaction. >> The timeout value for this completion will be the same as the current >> amount of time the I2C driver polls for. >> >> This will result in some performance improvement since the driver will be >> waiting for less time than it does right now on Apple Silicon hardware. >> >> The patch right now will only enable IRQs for Apple Silicon I2C chips, >> and only if it's able to successfully request the IRQ from the kernel. >> >> === Testing === >> >> This patch has been tested on both the mainline Linux kernel tree and >> the Asahi branch (https://github.com/AsahiLinux/linux.git) on both an >> M1 and M2 MacBook Air, and it compiles successfully as both a module and >> built-in to the kernel itself. The patch in both trees successfully boots >> to userspace without any hitch. >> >> I do not have PASemi hardware on hand unfortunately, so I'm unable to test >> the impact of this patch on old PASemi hardware. This is also why I've >> elected to do the IRQ request and enablement on the Apple platform driver >> and not in the common file, as I'm not sure if PASemi hardware supports >> IRQs. > I've added Darren and Christian to Cc, they have helped with PASemi > development and testing in the past, and may be able to help test this > series on PASemi hardware. > > cheers Tested-by: Christian Zigotzky <chzigotzky at xenosoft.de> on an A-EON AmigaOne X1000 with a PASemi PWRficient PA6T-1682 processor.
diff --git a/drivers/i2c/busses/i2c-pasemi-core.c b/drivers/i2c/busses/i2c-pasemi-core.c index 9028ffb58cc0..375aa9528233 100644 --- a/drivers/i2c/busses/i2c-pasemi-core.c +++ b/drivers/i2c/busses/i2c-pasemi-core.c @@ -21,6 +21,7 @@ #define REG_MTXFIFO 0x00 #define REG_MRXFIFO 0x04 #define REG_SMSTA 0x14 +#define REG_IMASK 0x18 #define REG_CTL 0x1c #define REG_REV 0x28 @@ -80,14 +81,21 @@ static int pasemi_smb_waitready(struct pasemi_smbus *smbus) { int timeout = 10; unsigned int status; + unsigned int bitmask = SMSTA_XEN | SMSTA_MTN; - status = reg_read(smbus, REG_SMSTA); - - while (!(status & SMSTA_XEN) && timeout--) { - msleep(1); + if (smbus->use_irq) { + reinit_completion(&smbus->irq_completion); + reg_write(smbus, REG_IMASK, bitmask); + wait_for_completion_timeout(&smbus->irq_completion, msecs_to_jiffies(10)); status = reg_read(smbus, REG_SMSTA); + } else { + while (!(status & SMSTA_XEN) && timeout--) { + msleep(1); + status = reg_read(smbus, REG_SMSTA); + } } + /* Got NACK? */ if (status & SMSTA_MTN) return -ENXIO; @@ -300,7 +308,7 @@ static int pasemi_smb_xfer(struct i2c_adapter *adapter, case I2C_SMBUS_BLOCK_DATA: case I2C_SMBUS_BLOCK_PROC_CALL: data->block[0] = len; - for (i = 1; i <= len; i ++) { + for (i = 1; i <= len; i++) { rd = RXFIFO_RD(smbus); if (rd & MRXFIFO_EMPTY) { err = -ENODATA; @@ -348,6 +356,8 @@ int pasemi_i2c_common_probe(struct pasemi_smbus *smbus) if (smbus->hw_rev != PASEMI_HW_REV_PCI) smbus->hw_rev = reg_read(smbus, REG_REV); + reg_write(smbus, REG_IMASK, 0); + pasemi_reset(smbus); error = devm_i2c_add_adapter(smbus->dev, &smbus->adapter); @@ -356,3 +366,12 @@ int pasemi_i2c_common_probe(struct pasemi_smbus *smbus) return 0; } + +irqreturn_t pasemi_irq_handler(int irq, void *dev_id) +{ + struct pasemi_smbus *smbus = (struct pasemi_smbus *)dev_id; + + reg_write(smbus, REG_IMASK, 0); + complete(&smbus->irq_completion); + return IRQ_HANDLED; +} diff --git a/drivers/i2c/busses/i2c-pasemi-core.h b/drivers/i2c/busses/i2c-pasemi-core.h index 4655124a37f3..045e4a9a3d13 100644 --- a/drivers/i2c/busses/i2c-pasemi-core.h +++ b/drivers/i2c/busses/i2c-pasemi-core.h @@ -7,6 +7,7 @@ #include <linux/i2c-smbus.h> #include <linux/io.h> #include <linux/kernel.h> +#include <linux/completion.h> #define PASEMI_HW_REV_PCI -1 @@ -16,6 +17,10 @@ struct pasemi_smbus { void __iomem *ioaddr; unsigned int clk_div; int hw_rev; + int use_irq; + struct completion irq_completion; }; int pasemi_i2c_common_probe(struct pasemi_smbus *smbus); + +irqreturn_t pasemi_irq_handler(int irq, void *dev_id); diff --git a/drivers/i2c/busses/i2c-pasemi-platform.c b/drivers/i2c/busses/i2c-pasemi-platform.c index 88a54aaf7e3c..ee1c84e7734b 100644 --- a/drivers/i2c/busses/i2c-pasemi-platform.c +++ b/drivers/i2c/busses/i2c-pasemi-platform.c @@ -49,6 +49,7 @@ static int pasemi_platform_i2c_probe(struct platform_device *pdev) struct pasemi_smbus *smbus; u32 frequency; int error; + int irq_num; data = devm_kzalloc(dev, sizeof(struct pasemi_platform_i2c_data), GFP_KERNEL); @@ -82,6 +83,13 @@ static int pasemi_platform_i2c_probe(struct platform_device *pdev) if (error) goto out_clk_disable; + smbus->use_irq = 0; + init_completion(&smbus->irq_completion); + irq_num = platform_get_irq(pdev, 0); + error = request_irq(irq_num, pasemi_irq_handler, 0, "pasemi_apple_i2c", (void *)smbus); + + if (!error) + smbus->use_irq = 1; platform_set_drvdata(pdev, data); return 0;
This is the first time I'm interacting with the Linux mailing lists, so please don't eviscerate me *too much* if I get the formatting wrong. Of course I'm always willing to take criticism and improve my formatting in the future. This patch adds support for IRQs to the PASemi I2C controller driver. This will allow for faster performing I2C transactions on Apple Silicon hardware, as previously, the driver was forced to poll the SMSTA register for a set amount of time. With this patchset the driver on Apple silicon hardware will instead wait for an interrupt which will signal the completion of the I2C transaction. The timeout value for this completion will be the same as the current amount of time the I2C driver polls for. This will result in some performance improvement since the driver will be waiting for less time than it does right now on Apple Silicon hardware. The patch right now will only enable IRQs for Apple Silicon I2C chips, and only if it's able to successfully request the IRQ from the kernel. === Testing === This patch has been tested on both the mainline Linux kernel tree and the Asahi branch (https://github.com/AsahiLinux/linux.git) on both an M1 and M2 MacBook Air, and it compiles successfully as both a module and built-in to the kernel itself. The patch in both trees successfully boots to userspace without any hitch. I do not have PASemi hardware on hand unfortunately, so I'm unable to test the impact of this patch on old PASemi hardware. This is also why I've elected to do the IRQ request and enablement on the Apple platform driver and not in the common file, as I'm not sure if PASemi hardware supports IRQs. I also fixed a quick checkpatch warning on line 303. "i ++" is now "i++". Any and all critiques of the patch would be well appreciated. Signed-off-by: Arminder Singh <arminders208@outlook.com> --- drivers/i2c/busses/i2c-pasemi-core.c | 29 ++++++++++++++++++++---- drivers/i2c/busses/i2c-pasemi-core.h | 5 ++++ drivers/i2c/busses/i2c-pasemi-platform.c | 8 +++++++ 3 files changed, 37 insertions(+), 5 deletions(-)