| Message ID | 1518794852-30137-1-git-send-email-clombard@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [V3] cxl: Fix timebase synchronization status on P9 | expand |
Hi Christophe, Mostly ok with this patch. Some very minor review comments: Christophe Lombard <clombard@linux.vnet.ibm.com> writes: > --- a/drivers/misc/cxl/sysfs.c > +++ b/drivers/misc/cxl/sysfs.c > @@ -62,6 +62,16 @@ static ssize_t psl_timebase_synced_show(struct device *device, > char *buf) > { > struct cxl *adapter = to_cxl_adapter(device); > + u64 psl_tb; > + int delta; > + > + psl_tb = adapter->native->sl_ops->timebase_read(adapter); > + delta = mftb() - psl_tb; > + if (delta < 0) > + delta = -delta; Can just use abs(). > + > + /* CORE TB and PSL TB difference <= 16usecs ? */ > + adapter->psl_timebase_synced = (tb_to_ns(delta) < 16000) ? true : false; Can be re-written as 'adapter->psl_timebase_synced = (tb_to_ns(abs(delta)) < 16000);' > > return scnprintf(buf, PAGE_SIZE, "%i\n", > adapter->psl_timebase_synced); Might be a good idea to debug print/print_once the delta.
Le 19/02/2018 à 07:10, Vaibhav Jain a écrit : > > Hi Christophe, > > Mostly ok with this patch. Some very minor review comments: > > Christophe Lombard <clombard@linux.vnet.ibm.com> writes: >> --- a/drivers/misc/cxl/sysfs.c >> +++ b/drivers/misc/cxl/sysfs.c >> @@ -62,6 +62,16 @@ static ssize_t psl_timebase_synced_show(struct device *device, >> char *buf) >> { >> struct cxl *adapter = to_cxl_adapter(device); >> + u64 psl_tb; >> + int delta; >> + >> + psl_tb = adapter->native->sl_ops->timebase_read(adapter); >> + delta = mftb() - psl_tb; >> + if (delta < 0) >> + delta = -delta; > Can just use abs(). okay, I can. >> + >> + /* CORE TB and PSL TB difference <= 16usecs ? */ >> + adapter->psl_timebase_synced = (tb_to_ns(delta) < 16000) ? true : false; > Can be re-written as > 'adapter->psl_timebase_synced = (tb_to_ns(abs(delta)) < 16000);' I prefer to keep the original version for easier reading. > >> >> return scnprintf(buf, PAGE_SIZE, "%i\n", >> adapter->psl_timebase_synced); > Might be a good idea to debug print/print_once the delta. sounds good. >
diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c index 66eed6a..3247eaf 100644 --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c @@ -606,9 +606,6 @@ static u64 timebase_read_xsl(struct cxl *adapter) static void cxl_setup_psl_timebase(struct cxl *adapter, struct pci_dev *dev) { - u64 psl_tb; - int delta; - unsigned int retry = 0; struct device_node *np; adapter->psl_timebase_synced = false; @@ -636,20 +633,6 @@ static void cxl_setup_psl_timebase(struct cxl *adapter, struct pci_dev *dev) cxl_p1_write(adapter, CXL_PSL_Control, 0x0000000000000000); cxl_p1_write(adapter, CXL_PSL_Control, CXL_PSL_Control_tb); - /* Wait until CORE TB and PSL TB difference <= 16usecs */ - do { - msleep(1); - if (retry++ > 5) { - dev_info(&dev->dev, "PSL timebase can't synchronize\n"); - return; - } - psl_tb = adapter->native->sl_ops->timebase_read(adapter); - delta = mftb() - psl_tb; - if (delta < 0) - delta = -delta; - } while (tb_to_ns(delta) > 16000); - - adapter->psl_timebase_synced = true; return; } diff --git a/drivers/misc/cxl/sysfs.c b/drivers/misc/cxl/sysfs.c index a8b6d6a..3f758d9 100644 --- a/drivers/misc/cxl/sysfs.c +++ b/drivers/misc/cxl/sysfs.c @@ -62,6 +62,16 @@ static ssize_t psl_timebase_synced_show(struct device *device, char *buf) { struct cxl *adapter = to_cxl_adapter(device); + u64 psl_tb; + int delta; + + psl_tb = adapter->native->sl_ops->timebase_read(adapter); + delta = mftb() - psl_tb; + if (delta < 0) + delta = -delta; + + /* CORE TB and PSL TB difference <= 16usecs ? */ + adapter->psl_timebase_synced = (tb_to_ns(delta) < 16000) ? true : false; return scnprintf(buf, PAGE_SIZE, "%i\n", adapter->psl_timebase_synced); }
The PSL Timebase register is updated by the PSL to maintain the timebase. On P9, the Timebase value is only provided by the CAPP as received the last time a timebase request was performed. The timebase requests are initiated through the adapter configuration or application registers. The specific sysfs entry "/sys/class/cxl/cardxx/psl_timebase_synced" is now dynamically updated according the content of the PSL Timebase register. Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> --- This patch applies on top of this patch: http://patchwork.ozlabs.org/patch/873663/ Changelog[v3] - Rebased to latest upstream. - Dynamic update is now applied to P8. Changelog[v2] - Missing Signed-off-by. - Spaces required around the ':'. --- drivers/misc/cxl/pci.c | 17 ----------------- drivers/misc/cxl/sysfs.c | 10 ++++++++++ 2 files changed, 10 insertions(+), 17 deletions(-)