Re: [PATCH] coresight: cti: Fix remove sysfs link error.

On Tue, 21 Jul 2020 at 13:50, Mike Leach mike.leach@linaro.org wrote:

Hi Mathieu,

On Tue, 21 Jul 2020 at 18:51, Mathieu Poirier mathieu.poirier@linaro.org wrote:

...

Hi Mike,

On Tue, Jul 21, 2020 at 12:17:36PM +0100, Mike Leach wrote:

...

CTI code to remove sysfs link to other devices on shutdown, incorrectly tries to remove a single ended link when these are all double ended. This implementation leaves elements in the link info structure undefined which results in a crash in recent tests for driver module unload.

This patch corrects the link removal code.

Fixes: 73274abb6557 (coresight: cti: Add in sysfs links to other coresight devices)

Please remove the extra new line, add a "Reported-by:" for Tingwei and remove the '.' at the end of the title. Up to now I've been removing those manually but it causes problems when Greg has to pickup a set directly from the mailing list.

Will do.

...

Also, I just noticed the other problem you shared with Tingwei regarding the call to cti_remove_conn_xrefs() in cti_remove(). I think it will be simpler if you send a 2 patch serie with those fixes.

The issue here is that this patch is completely independent of Tingwei's coresight module set, and applies immediately to coresight\next.

The additional change I suggested to completely fix the problem is entirely dependent on changes (i.e. the introduction of cti_remove()) made by Tingwei and thus dependent on that set.

Ok

Thus I cannot issue a 2 patch set without Tingwei re-working the module set, and the resulting set would be dependent on that set, leaving the coresight module set broken until a second set is applied.

My expectation was that Tingwei would include the cti_remove() suggested change as part of his re-work while rebasing on coresight/next, leaving this patch to be applied before / afterwards.

Alternatively, this patch could simply become another patch in Tingwei's coresight module series. (the issue it fixes doesn't appear to have adverse effects when coresight drivers are built in).

This is a better way - Tingwei please include Mike's patch in your next revision.

Thanks, Mathieu

Regards

Mike

...

Thanks, Mathieu

...

Signed-off-by: Mike Leach mike.leach@linaro.org

drivers/hwtracing/coresight/coresight-cti.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-cti.c b/drivers/hwtracing/coresight/coresight-cti.c index 3ccc703dc940..19d0b031a7df 100644 --- a/drivers/hwtracing/coresight/coresight-cti.c +++ b/drivers/hwtracing/coresight/coresight-cti.c @@ -511,12 +511,15 @@ static bool cti_add_sysfs_link(struct cti_drvdata *drvdata, return !link_err; }

-static void cti_remove_sysfs_link(struct cti_trig_con *tc) +static void cti_remove_sysfs_link(struct cti_drvdata *drvdata,

•                           struct cti_trig_con *tc)
  

{ struct coresight_sysfs_link link_info;

• link_info.orig = drvdata->csdev;
  link_info.orig_name = tc->con_dev_name;
  link_info.target = tc->con_dev;
  

• link_info.target_name = dev_name(&drvdata->csdev->dev);
  coresight_remove_sysfs_link(&link_info);
  

}

@@ -607,7 +610,7 @@ void cti_remove_assoc_from_csdev(struct coresight_device *csdev) ctidev = &ctidrv->ctidev; list_for_each_entry(tc, &ctidev->trig_cons, node) { if (tc->con_dev == csdev->ect_dev) {

•                         cti_remove_sysfs_link(tc);
  

•                         cti_remove_sysfs_link(ctidrv, tc);
                          tc->con_dev = NULL;
                          break;
                  }
  

@@ -651,7 +654,7 @@ static void cti_remove_conn_xrefs(struct cti_drvdata *drvdata) if (tc->con_dev) { coresight_set_assoc_ectdev_mutex(tc->con_dev, NULL);

•                 cti_remove_sysfs_link(tc);
  

•                 cti_remove_sysfs_link(drvdata, tc);
                  tc->con_dev = NULL;
          }
  }
  

-- 2.17.1

-- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK