| Message ID | 20230217-topic-icc-fixes-v5-v5-1-c9a550f9fdb9@linaro.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | The great interconnecification fixation | expand |
On 17/02/2023 10:46, Konrad Dybcio wrote: I find this commit log difficult to understand. Could you reduce it down ? > Currently, NOC_QOS_MODE_FIXED is defined as 0x0, which makes it the > "default" option (as that's what uninitialized members of partially > initialized structs are set to), which should really have been > NOC_QOS_MODE_INVALID, and that's what people (wrongly) assumed was > the case when .qos.qos_mode was not defined and what really makes > the most sense.. "Currently NOC_QOS_MODE_FIXED is defined as 0x0 which makes it the default option. The default option however should be NOC_QOS_MODE_INVALID" > That resulted in {port 0, prio 0, areq_prio 0, urg_fwd = false, rpm-voted} > QoS being always voted for, because the code flow assumed "hey, it's fixed > QoS, so let's just roll with whatever parameters are set" [again, set by > partial struct initialization, as these fields were left unfilled by the > developers]. That is of course incorrect, and on many of these platforms > port 0 is MAS_APPS_PROC, which 9/10 times is supposed to be handled by > the ap_owned path, not to mention the rest of the parameters may differ. > Arguably, the APPS node is the most important one, next to EBI0.. This paragraph in particular is difficult to decipher, at least for me with my native Dublinese > The modes are defined as preprocessor constants. They are not used > anywhere outside the driver or sent to any remote processor outside > qcom_icc_set_noc_qos(), which is easily worked around. > Separate the type specified in driver data from the value sent to msmbus. > Make the former an enum for better mainainability. > > This is an implicit fix for every SMD RPM ICC driver that didn't > explicitly specify NOC_QOS_MODE_INVALID on non-AP_owned nodes that > don't have QoS settings. It would be nice to reduce the commit log down to say three paragraphs of no more than three sentences each. --- bod
diff --git a/drivers/interconnect/qcom/icc-rpm.c b/drivers/interconnect/qcom/icc-rpm.c index df3196f72536..ffbeeca8c2b0 100644 --- a/drivers/interconnect/qcom/icc-rpm.c +++ b/drivers/interconnect/qcom/icc-rpm.c @@ -48,6 +48,9 @@ #define NOC_QOS_MODEn_ADDR(n) (0xc + (n * 0x1000)) #define NOC_QOS_MODEn_MASK 0x3 +#define NOC_QOS_MODE_FIXED_VAL 0x0 +#define NOC_QOS_MODE_BYPASS_VAL 0x2 + static int qcom_icc_set_qnoc_qos(struct icc_node *src, u64 max_bw) { struct icc_provider *provider = src->provider; @@ -153,7 +156,7 @@ static int qcom_icc_set_noc_qos(struct icc_node *src, u64 max_bw) struct qcom_icc_provider *qp; struct qcom_icc_node *qn; struct icc_provider *provider; - u32 mode = NOC_QOS_MODE_BYPASS; + u32 mode = NOC_QOS_MODE_BYPASS_VAL; int rc = 0; qn = src->data; @@ -167,18 +170,17 @@ static int qcom_icc_set_noc_qos(struct icc_node *src, u64 max_bw) return 0; } - if (qn->qos.qos_mode != NOC_QOS_MODE_INVALID) - mode = qn->qos.qos_mode; - - if (mode == NOC_QOS_MODE_FIXED) { - dev_dbg(src->provider->dev, "NoC QoS: %s: Set Fixed mode\n", - qn->name); + if (qn->qos.qos_mode == NOC_QOS_MODE_FIXED) { + dev_dbg(src->provider->dev, "NoC QoS: %s: Set Fixed mode\n", qn->name); + mode = NOC_QOS_MODE_FIXED_VAL; rc = qcom_icc_noc_set_qos_priority(qp, &qn->qos); if (rc) return rc; - } else if (mode == NOC_QOS_MODE_BYPASS) { - dev_dbg(src->provider->dev, "NoC QoS: %s: Set Bypass mode\n", - qn->name); + } else if (qn->qos.qos_mode == NOC_QOS_MODE_BYPASS) { + dev_dbg(src->provider->dev, "NoC QoS: %s: Set Bypass mode\n", qn->name); + mode = NOC_QOS_MODE_BYPASS_VAL; + } else { + /* How did we get here? */ } return regmap_update_bits(qp->regmap, @@ -244,7 +246,7 @@ static int __qcom_icc_set(struct icc_node *n, struct qcom_icc_node *qn, ret = qcom_icc_rpm_set(qn->mas_rpm_id, qn->slv_rpm_id, sum_bw); if (ret) return ret; - } else if (qn->qos.qos_mode != -1) { + } else if (qn->qos.qos_mode != NOC_QOS_MODE_INVALID) { /* set bandwidth directly from the AP */ ret = qcom_icc_qos_set(n, sum_bw); if (ret) diff --git a/drivers/interconnect/qcom/icc-rpm.h b/drivers/interconnect/qcom/icc-rpm.h index a49af844ab13..8ba1918d7997 100644 --- a/drivers/interconnect/qcom/icc-rpm.h +++ b/drivers/interconnect/qcom/icc-rpm.h @@ -97,10 +97,12 @@ struct qcom_icc_desc { unsigned int qos_offset; }; -/* Valid for both NoC and BIMC */ -#define NOC_QOS_MODE_INVALID -1 -#define NOC_QOS_MODE_FIXED 0x0 -#define NOC_QOS_MODE_BYPASS 0x2 +/* Valid for all bus types */ +enum qos_mode { + NOC_QOS_MODE_INVALID = 0, + NOC_QOS_MODE_FIXED, + NOC_QOS_MODE_BYPASS, +}; int qnoc_probe(struct platform_device *pdev); int qnoc_remove(struct platform_device *pdev);
Currently, NOC_QOS_MODE_FIXED is defined as 0x0, which makes it the "default" option (as that's what uninitialized members of partially initialized structs are set to), which should really have been NOC_QOS_MODE_INVALID, and that's what people (wrongly) assumed was the case when .qos.qos_mode was not defined and what really makes the most sense.. That resulted in {port 0, prio 0, areq_prio 0, urg_fwd = false, rpm-voted} QoS being always voted for, because the code flow assumed "hey, it's fixed QoS, so let's just roll with whatever parameters are set" [again, set by partial struct initialization, as these fields were left unfilled by the developers]. That is of course incorrect, and on many of these platforms port 0 is MAS_APPS_PROC, which 9/10 times is supposed to be handled by the ap_owned path, not to mention the rest of the parameters may differ. Arguably, the APPS node is the most important one, next to EBI0.. The modes are defined as preprocessor constants. They are not used anywhere outside the driver or sent to any remote processor outside qcom_icc_set_noc_qos(), which is easily worked around. Separate the type specified in driver data from the value sent to msmbus. Make the former an enum for better mainainability. This is an implicit fix for every SMD RPM ICC driver that didn't explicitly specify NOC_QOS_MODE_INVALID on non-AP_owned nodes that don't have QoS settings. Fixes: 30c8fa3ec61a ("interconnect: qcom: Add MSM8916 interconnect provider driver") Fixes: 6c6fe5d3dc5e ("interconnect: qcom: Add MSM8939 interconnect provider driver") Fixes: 4e60a9568dc6 ("interconnect: qcom: add msm8974 driver") Fixes: 7add937f5222 ("interconnect: qcom: Add MSM8996 interconnect provider driver") Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org> --- drivers/interconnect/qcom/icc-rpm.c | 24 +++++++++++++----------- drivers/interconnect/qcom/icc-rpm.h | 10 ++++++---- 2 files changed, 19 insertions(+), 15 deletions(-)