| Message ID | 1523433162-3910-1-git-send-email-baijiaju1990@gmail.com |
|---|---|
| State | Rejected |
| Delegated to: | David Miller |
| Headers | show |
| Series | [1/2] ide: pdc202xx_new: Replace mdelay with usleep_range in detect_pll_input_clock | expand |
Hello! On 4/11/2018 10:52 AM, Jia-Ju Bai wrote: > detect_pll_input_clock() is never called in atomic context. > > detect_pll_input_clock() is only called by init_chipset_pdcnew(), which > is set as ".init_chipset" in struct ide_port_info. > This function is not called in atomic context. > > Despite never getting called from atomic context, detect_pll_input_clock() > calls mdelay() to busily wait. > This is not necessary and can be replaced with usleep_range() to > avoid busy waiting. > > This is found by a static analysis tool named DCNS written by myself. > And I also manually check it. > > Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> > --- > drivers/ide/pdc202xx_new.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/ide/pdc202xx_new.c b/drivers/ide/pdc202xx_new.c > index b33646b..6afa66d 100644 > --- a/drivers/ide/pdc202xx_new.c > +++ b/drivers/ide/pdc202xx_new.c > @@ -258,7 +258,7 @@ static long detect_pll_input_clock(unsigned long dma_base) > outb(scr1 | 0x40, dma_base + 0x03); > > /* Let the counter run for 10 ms. */ > - mdelay(10); > + usleep_range(10); This function takes 2 arguments. [...] MBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2018/4/11 16:33, Sergei Shtylyov wrote: > Hello! > > On 4/11/2018 10:52 AM, Jia-Ju Bai wrote: > >> detect_pll_input_clock() is never called in atomic context. >> >> detect_pll_input_clock() is only called by init_chipset_pdcnew(), which >> is set as ".init_chipset" in struct ide_port_info. >> This function is not called in atomic context. >> >> Despite never getting called from atomic context, >> detect_pll_input_clock() >> calls mdelay() to busily wait. >> This is not necessary and can be replaced with usleep_range() to >> avoid busy waiting. >> >> This is found by a static analysis tool named DCNS written by myself. >> And I also manually check it. >> >> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> >> --- >> drivers/ide/pdc202xx_new.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/ide/pdc202xx_new.c b/drivers/ide/pdc202xx_new.c >> index b33646b..6afa66d 100644 >> --- a/drivers/ide/pdc202xx_new.c >> +++ b/drivers/ide/pdc202xx_new.c >> @@ -258,7 +258,7 @@ static long detect_pll_input_clock(unsigned long >> dma_base) >> outb(scr1 | 0x40, dma_base + 0x03); >> /* Let the counter run for 10 ms. */ >> - mdelay(10); >> + usleep_range(10); > > This function takes 2 arguments. > > [...] > > MBR, Sergei Oops, sorry for my fault. Thanks for telling me this :) I will modify it and send V2. Best wishes, Jia-Ju Bai -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Jia-Ju,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on ide/master]
[also build test ERROR on v4.16 next-20180411]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Jia-Ju-Bai/ide-pdc202xx_new-Replace-mdelay-with-usleep_range-in-detect_pll_input_clock/20180412-105416
base: https://git.kernel.org/pub/scm/linux/kernel/git/davem/ide.git master
config: i386-randconfig-x015-201814 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
All errors (new ones prefixed by >>):
drivers//ide/pdc202xx_new.c: In function 'detect_pll_input_clock':
>> drivers//ide/pdc202xx_new.c:261:2: error: too few arguments to function 'usleep_range'
usleep_range(10);
^~~~~~~~~~~~
In file included from drivers//ide/pdc202xx_new.c:21:0:
include/linux/delay.h:60:6: note: declared here
void usleep_range(unsigned long min, unsigned long max);
^~~~~~~~~~~~
vim +/usleep_range +261 drivers//ide/pdc202xx_new.c
238
239 /**
240 * detect_pll_input_clock - Detect the PLL input clock in Hz.
241 * @dma_base: for the port address
242 * E.g. 16949000 on 33 MHz PCI bus, i.e. half of the PCI clock.
243 */
244 static long detect_pll_input_clock(unsigned long dma_base)
245 {
246 ktime_t start_time, end_time;
247 long start_count, end_count;
248 long pll_input, usec_elapsed;
249 u8 scr1;
250
251 start_count = read_counter(dma_base);
252 start_time = ktime_get();
253
254 /* Start the test mode */
255 outb(0x01, dma_base + 0x01);
256 scr1 = inb(dma_base + 0x03);
257 DBG("scr1[%02X]\n", scr1);
258 outb(scr1 | 0x40, dma_base + 0x03);
259
260 /* Let the counter run for 10 ms. */
> 261 usleep_range(10);
262
263 end_count = read_counter(dma_base);
264 end_time = ktime_get();
265
266 /* Stop the test mode */
267 outb(0x01, dma_base + 0x01);
268 scr1 = inb(dma_base + 0x03);
269 DBG("scr1[%02X]\n", scr1);
270 outb(scr1 & ~0x40, dma_base + 0x03);
271
272 /*
273 * Calculate the input clock in Hz
274 * (the clock counter is 30 bit wide and counts down)
275 */
276 usec_elapsed = ktime_us_delta(end_time, start_time);
277 pll_input = ((start_count - end_count) & 0x3fffffff) / 10 *
278 (10000000 / usec_elapsed);
279
280 DBG("start[%ld] end[%ld]\n", start_count, end_count);
281
282 return pll_input;
283 }
284
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
diff --git a/drivers/ide/pdc202xx_new.c b/drivers/ide/pdc202xx_new.c index b33646b..6afa66d 100644 --- a/drivers/ide/pdc202xx_new.c +++ b/drivers/ide/pdc202xx_new.c @@ -258,7 +258,7 @@ static long detect_pll_input_clock(unsigned long dma_base) outb(scr1 | 0x40, dma_base + 0x03); /* Let the counter run for 10 ms. */ - mdelay(10); + usleep_range(10); end_count = read_counter(dma_base); end_time = ktime_get();
detect_pll_input_clock() is never called in atomic context. detect_pll_input_clock() is only called by init_chipset_pdcnew(), which is set as ".init_chipset" in struct ide_port_info. This function is not called in atomic context. Despite never getting called from atomic context, detect_pll_input_clock() calls mdelay() to busily wait. This is not necessary and can be replaced with usleep_range() to avoid busy waiting. This is found by a static analysis tool named DCNS written by myself. And I also manually check it. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- drivers/ide/pdc202xx_new.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)