| Message ID | 164730736948.3806189.17828261054974867700.stgit@dwillia2-desk3.amr.corp.intel.com |
|---|---|
| State | New, archived |
| Headers | show |
| Series | cxl: Handle DVSEC range init failures | expand |
On Mon, 14 Mar 2022 18:22:49 -0700 Dan Williams <dan.j.williams@intel.com> wrote: > cxl_mem_probe() already emits a log message when HDM operation can not > be established. Delete the similar one in cxl_hdm_decode_init(). > > What is less obvious is why global_ctrl being enabled makes positive > values of info->ranges irrelevant. > > Signed-off-by: Dan Williams <dan.j.williams@intel.com> Assuming comment on ignore recommendation added for v3. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > --- > drivers/cxl/mem.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c > index 3baae1332760..6def7d7b6bfd 100644 > --- a/drivers/cxl/mem.c > +++ b/drivers/cxl/mem.c > @@ -107,11 +107,16 @@ __mock bool cxl_hdm_decode_init(struct cxl_dev_state *cxlds) > global_ctrl = readl(crb + cmap->hdm_decoder.offset + > CXL_HDM_DECODER_CTRL_OFFSET); > global_enable = global_ctrl & CXL_HDM_DECODER_ENABLE; > - if (!global_enable && info->ranges) { > - dev_dbg(cxlds->dev, > - "DVSEC ranges already programmed and HDM decoders not enabled.\n"); > + > + /* > + * Per CXL 2.0 Section 8.1.3.8.3 and 8.1.3.8.4 DVSEC CXL Range 1 Base > + * [High,Low] when HDM operation is enabled the range register values > + * are ignored by the device, but the spec also recommends matching the > + * DVSEC Range 1,2 to HDM Decoder Range 0,1 so, non-zero info->ranges > + * are expected. > + */ > + if (!global_enable && info->ranges) > goto out; > - } > > retval = true; > >
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index 3baae1332760..6def7d7b6bfd 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -107,11 +107,16 @@ __mock bool cxl_hdm_decode_init(struct cxl_dev_state *cxlds) global_ctrl = readl(crb + cmap->hdm_decoder.offset + CXL_HDM_DECODER_CTRL_OFFSET); global_enable = global_ctrl & CXL_HDM_DECODER_ENABLE; - if (!global_enable && info->ranges) { - dev_dbg(cxlds->dev, - "DVSEC ranges already programmed and HDM decoders not enabled.\n"); + + /* + * Per CXL 2.0 Section 8.1.3.8.3 and 8.1.3.8.4 DVSEC CXL Range 1 Base + * [High,Low] when HDM operation is enabled the range register values + * are ignored by the device, but the spec also recommends matching the + * DVSEC Range 1,2 to HDM Decoder Range 0,1 so, non-zero info->ranges + * are expected. + */ + if (!global_enable && info->ranges) goto out; - } retval = true;
cxl_mem_probe() already emits a log message when HDM operation can not be established. Delete the similar one in cxl_hdm_decode_init(). What is less obvious is why global_ctrl being enabled makes positive values of info->ranges irrelevant. Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- drivers/cxl/mem.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)