2021-04-15 05:42:23

by Artur Petrosyan

[permalink] [raw]
Subject: [PATCH 13/15] usb: dwc2: Add exit hibernation mode before removing drive

When dwc2 core is in hibernation mode loading
driver again causes driver fail. Because in
that mode registers are not accessible.

In order to exit from hibernation checking
dwc2 core power saving state in "dwc2_driver_remove()"
function. If core is in hibernation, then checking the
operational mode of the driver. To check whether dwc2 core
is operating in host mode or device mode there is one way
which is retrieving the backup value of "gotgctl" and compare
the "CurMod" value. If previously core entered hibernation
in host mode then the exit is performed for host if not then
exit is performed for device mode. The introduced checking
is because in hibernation state all registers are not
accessible.

Signed-off-by: Artur Petrosyan <[email protected]>
---
drivers/usb/dwc2/platform.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index f8b819cfa80e..2ae4748ed5ec 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -316,8 +316,24 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
static int dwc2_driver_remove(struct platform_device *dev)
{
struct dwc2_hsotg *hsotg = platform_get_drvdata(dev);
+ struct dwc2_gregs_backup *gr;
int ret = 0;

+ /* Exit Hibernation when driver is removed. */
+ if (hsotg->hibernated) {
+ if (gr->gotgctl & GOTGCTL_CURMODE_HOST) {
+ ret = dwc2_exit_hibernation(hsotg, 0, 0, 1);
+ if (ret)
+ dev_err(hsotg->dev,
+ "exit hibernation failed.\n");
+ } else {
+ ret = dwc2_exit_hibernation(hsotg, 0, 0, 0);
+ if (ret)
+ dev_err(hsotg->dev,
+ "exit hibernation failed.\n");
+ }
+ }
+
/* Exit Partial Power Down when driver is removed. */
if (hsotg->in_ppd) {
ret = dwc2_exit_partial_power_down(hsotg, 0, true);
--
2.25.1


2021-04-15 09:27:56

by Sergei Shtylyov

[permalink] [raw]
Subject: Re: [PATCH 13/15] usb: dwc2: Add exit hibernation mode before removing drive

On 15.04.2021 8:41, Artur Petrosyan wrote:

> When dwc2 core is in hibernation mode loading
> driver again causes driver fail. Because in
> that mode registers are not accessible.
>
> In order to exit from hibernation checking
> dwc2 core power saving state in "dwc2_driver_remove()"
> function. If core is in hibernation, then checking the
> operational mode of the driver. To check whether dwc2 core
> is operating in host mode or device mode there is one way
> which is retrieving the backup value of "gotgctl" and compare
> the "CurMod" value. If previously core entered hibernation
> in host mode then the exit is performed for host if not then
> exit is performed for device mode. The introduced checking
> is because in hibernation state all registers are not
> accessible.
>
> Signed-off-by: Artur Petrosyan <[email protected]>
> ---
> drivers/usb/dwc2/platform.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
> index f8b819cfa80e..2ae4748ed5ec 100644
> --- a/drivers/usb/dwc2/platform.c
> +++ b/drivers/usb/dwc2/platform.c
> @@ -316,8 +316,24 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
> static int dwc2_driver_remove(struct platform_device *dev)
> {
> struct dwc2_hsotg *hsotg = platform_get_drvdata(dev);
> + struct dwc2_gregs_backup *gr;
> int ret = 0;
>
> + /* Exit Hibernation when driver is removed. */
> + if (hsotg->hibernated) {
> + if (gr->gotgctl & GOTGCTL_CURMODE_HOST) {
> + ret = dwc2_exit_hibernation(hsotg, 0, 0, 1);
> + if (ret)
> + dev_err(hsotg->dev,
> + "exit hibernation failed.\n");
> + } else {
> + ret = dwc2_exit_hibernation(hsotg, 0, 0, 0);
> + if (ret)
> + dev_err(hsotg->dev,
> + "exit hibernation failed.\n");

Again, why duplicate the innermost *if*?

> + }
> + }
> +
> /* Exit Partial Power Down when driver is removed. */
> if (hsotg->in_ppd) {
> ret = dwc2_exit_partial_power_down(hsotg, 0, true);

MBR, Sergei

2021-04-15 09:53:12

by kernel test robot

[permalink] [raw]
Subject: Re: [PATCH 13/15] usb: dwc2: Add exit hibernation mode before removing drive

Hi Artur,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on usb/usb-testing]
[also build test WARNING on next-20210414]
[cannot apply to peter.chen-usb/for-usb-next linus/master balbi-usb/testing/next v5.12-rc7]
[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]

url: https://github.com/0day-ci/linux/commits/Artur-Petrosyan/usb-dwc2-Update-exit-hibernation-when-port-reset-is-asserted/20210415-144021
base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
config: x86_64-randconfig-a014-20210415 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 6a18cc23efad410db48a3ccfc233d215de7d4cb9)
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 x86_64 cross compiling tool for clang build
# apt-get install binutils-x86-64-linux-gnu
# https://github.com/0day-ci/linux/commit/8e4dbc0200040af9c752aca4090cd41572e6fb86
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Artur-Petrosyan/usb-dwc2-Update-exit-hibernation-when-port-reset-is-asserted/20210415-144021
git checkout 8e4dbc0200040af9c752aca4090cd41572e6fb86
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=x86_64

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>

All warnings (new ones prefixed by >>):

>> drivers/usb/dwc2/platform.c:324:7: warning: variable 'gr' is uninitialized when used here [-Wuninitialized]
if (gr->gotgctl & GOTGCTL_CURMODE_HOST) {
^~
drivers/usb/dwc2/platform.c:319:30: note: initialize the variable 'gr' to silence this warning
struct dwc2_gregs_backup *gr;
^
= NULL
1 warning generated.


vim +/gr +324 drivers/usb/dwc2/platform.c

304
305 /**
306 * dwc2_driver_remove() - Called when the DWC_otg core is unregistered with the
307 * DWC_otg driver
308 *
309 * @dev: Platform device
310 *
311 * This routine is called, for example, when the rmmod command is executed. The
312 * device may or may not be electrically present. If it is present, the driver
313 * stops device processing. Any resources used on behalf of this device are
314 * freed.
315 */
316 static int dwc2_driver_remove(struct platform_device *dev)
317 {
318 struct dwc2_hsotg *hsotg = platform_get_drvdata(dev);
319 struct dwc2_gregs_backup *gr;
320 int ret = 0;
321
322 /* Exit Hibernation when driver is removed. */
323 if (hsotg->hibernated) {
> 324 if (gr->gotgctl & GOTGCTL_CURMODE_HOST) {
325 ret = dwc2_exit_hibernation(hsotg, 0, 0, 1);
326 if (ret)
327 dev_err(hsotg->dev,
328 "exit hibernation failed.\n");
329 } else {
330 ret = dwc2_exit_hibernation(hsotg, 0, 0, 0);
331 if (ret)
332 dev_err(hsotg->dev,
333 "exit hibernation failed.\n");
334 }
335 }
336
337 /* Exit Partial Power Down when driver is removed. */
338 if (hsotg->in_ppd) {
339 ret = dwc2_exit_partial_power_down(hsotg, 0, true);
340 if (ret)
341 dev_err(hsotg->dev,
342 "exit partial_power_down failed\n");
343 }
344
345 /* Exit clock gating when driver is removed. */
346 if (hsotg->params.power_down == DWC2_POWER_DOWN_PARAM_NONE &&
347 hsotg->bus_suspended) {
348 if (dwc2_is_device_mode(hsotg))
349 dwc2_gadget_exit_clock_gating(hsotg, 0);
350 else
351 dwc2_host_exit_clock_gating(hsotg, 0);
352 }
353
354 dwc2_debugfs_exit(hsotg);
355 if (hsotg->hcd_enabled)
356 dwc2_hcd_remove(hsotg);
357 if (hsotg->gadget_enabled)
358 dwc2_hsotg_remove(hsotg);
359
360 dwc2_drd_exit(hsotg);
361
362 if (hsotg->params.activate_stm_id_vb_detection)
363 regulator_disable(hsotg->usb33d);
364
365 if (hsotg->ll_hw_enabled)
366 dwc2_lowlevel_hw_disable(hsotg);
367
368 reset_control_assert(hsotg->reset);
369 reset_control_assert(hsotg->reset_ecc);
370
371 return ret;
372 }
373

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]


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2021-04-16 06:04:26

by Artur Petrosyan

[permalink] [raw]
Subject: Re: [PATCH 13/15] usb: dwc2: Add exit hibernation mode before removing drive

Hi Sergei,

On 4/15/2021 13:24, Sergei Shtylyov wrote:
> On 15.04.2021 8:41, Artur Petrosyan wrote:
>
>> When dwc2 core is in hibernation mode loading
>> driver again causes driver fail. Because in
>> that mode registers are not accessible.
>>
>> In order to exit from hibernation checking
>> dwc2 core power saving state in "dwc2_driver_remove()"
>> function. If core is in hibernation, then checking the
>> operational mode of the driver. To check whether dwc2 core
>> is operating in host mode or device mode there is one way
>> which is retrieving the backup value of "gotgctl" and compare
>> the "CurMod" value. If previously core entered hibernation
>> in host mode then the exit is performed for host if not then
>> exit is performed for device mode. The introduced checking
>> is because in hibernation state all registers are not
>> accessible.
>>
>> Signed-off-by: Artur Petrosyan <[email protected]>
>> ---
>> drivers/usb/dwc2/platform.c | 16 ++++++++++++++++
>> 1 file changed, 16 insertions(+)
>>
>> diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
>> index f8b819cfa80e..2ae4748ed5ec 100644
>> --- a/drivers/usb/dwc2/platform.c
>> +++ b/drivers/usb/dwc2/platform.c
>> @@ -316,8 +316,24 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
>> static int dwc2_driver_remove(struct platform_device *dev)
>> {
>> struct dwc2_hsotg *hsotg = platform_get_drvdata(dev);
>> + struct dwc2_gregs_backup *gr;
>> int ret = 0;
>>
>> + /* Exit Hibernation when driver is removed. */
>> + if (hsotg->hibernated) {
>> + if (gr->gotgctl & GOTGCTL_CURMODE_HOST) {
>> + ret = dwc2_exit_hibernation(hsotg, 0, 0, 1);
>> + if (ret)
>> + dev_err(hsotg->dev,
>> + "exit hibernation failed.\n");
>> + } else {
>> + ret = dwc2_exit_hibernation(hsotg, 0, 0, 0);
>> + if (ret)
>> + dev_err(hsotg->dev,
>> + "exit hibernation failed.\n");
>
> Again, why duplicate the innermost *if*?
Again the reason is that combination of inner and outside ifs would give
as a situation when core would not be hibernated but driver would try to
exit from host or device hibernation.

>
>> + }
>> + }
>> +
>> /* Exit Partial Power Down when driver is removed. */
>> if (hsotg->in_ppd) {
>> ret = dwc2_exit_partial_power_down(hsotg, 0, true);
>
> MBR, Sergei
>
Regards,
Artur