diff mbox series

[13/15] usb: dwc2: Add exit hibernation mode before removing drive

Message ID d01d23e2473407af37c42acb6ca4815ae5fd256e.1618464534.git.Arthur.Petrosyan@synopsys.com (mailing list archive)
State New, archived
Headers show
Series [01/15] usb: dwc2: Update exit hibernation when port reset is asserted | expand

Commit Message

Artur Petrosyan April 15, 2021, 5:41 a.m. UTC
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 <Arthur.Petrosyan@synopsys.com>
---
 drivers/usb/dwc2/platform.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

Comments

Sergey Shtylyov April 15, 2021, 9:24 a.m. UTC | #1
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 <Arthur.Petrosyan@synopsys.com>
> ---
>   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
kernel test robot April 15, 2021, 9:50 a.m. UTC | #2
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 <lkp@intel.com>

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/kbuild-all@lists.01.org
Dan Carpenter April 15, 2021, 1:40 p.m. UTC | #3
Hi Artur,

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: i386-randconfig-m021-20210415 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

smatch warnings:
drivers/usb/dwc2/platform.c:324 dwc2_driver_remove() error: potentially dereferencing uninitialized 'gr'.

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

5b9974b13e3648 drivers/staging/dwc2/platform.c Matthijs Kooijman  2013-04-22  316  static int dwc2_driver_remove(struct platform_device *dev)
5b9974b13e3648 drivers/staging/dwc2/platform.c Matthijs Kooijman  2013-04-22  317  {
5b9974b13e3648 drivers/staging/dwc2/platform.c Matthijs Kooijman  2013-04-22  318  	struct dwc2_hsotg *hsotg = platform_get_drvdata(dev);
8e4dbc0200040a drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-15  319  	struct dwc2_gregs_backup *gr;
                                                                                                                  ^^
b46b1ef7b0da5c drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-08  320  	int ret = 0;
b46b1ef7b0da5c drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-08  321  
8e4dbc0200040a drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-15  322  	/* Exit Hibernation when driver is removed. */
8e4dbc0200040a drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-15  323  	if (hsotg->hibernated) {
8e4dbc0200040a drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-15 @324  		if (gr->gotgctl & GOTGCTL_CURMODE_HOST) {
                                                                                                    ^^^^^^^^^^^
8e4dbc0200040a drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-15  325  			ret = dwc2_exit_hibernation(hsotg, 0, 0, 1);
8e4dbc0200040a drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-15  326  			if (ret)
8e4dbc0200040a drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-15  327  				dev_err(hsotg->dev,
8e4dbc0200040a drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-15  328  					"exit hibernation failed.\n");
8e4dbc0200040a drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-15  329  		} else {
8e4dbc0200040a drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-15  330  			ret = dwc2_exit_hibernation(hsotg, 0, 0, 0);
8e4dbc0200040a drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-15  331  			if (ret)
8e4dbc0200040a drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-15  332  				dev_err(hsotg->dev,
8e4dbc0200040a drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-15  333  					"exit hibernation failed.\n");
8e4dbc0200040a drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-15  334  		}
8e4dbc0200040a drivers/usb/dwc2/platform.c     Artur Petrosyan    2021-04-15  335  	}

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Artur Petrosyan April 16, 2021, 5:46 a.m. UTC | #4
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 <Arthur.Petrosyan@synopsys.com>
>> ---
>>    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
diff mbox series

Patch

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);