* [PATCH v2 3/5] soc: qcom: socinfo: Expose custom attributes @ 2019-02-20 4:58 Vaishali Thakkar 2019-02-21 12:18 ` Laurent Pinchart 0 siblings, 1 reply; 8+ messages in thread From: Vaishali Thakkar @ 2019-02-20 4:58 UTC (permalink / raw) To: andy.gross Cc: david.brown, gregkh, linux-arm-msm, linux-kernel, rafael, bjorn.andersson, vkoul, Vaishali Thakkar The Qualcomm socinfo provides a number of additional attributes, add these to the socinfo driver and expose them via debugfs functionality. Signed-off-by: Vaishali Thakkar <vaishali.thakkar@linaro.org> --- Changes since v1: - Remove unnecessary debugfs dir creation check - Align ifdefs to left - Fix function signatures for debugfs init/exit --- drivers/soc/qcom/socinfo.c | 198 +++++++++++++++++++++++++++++++++++++ 1 file changed, 198 insertions(+) diff --git a/drivers/soc/qcom/socinfo.c b/drivers/soc/qcom/socinfo.c index 02078049fac7..5f4bef216ae1 100644 --- a/drivers/soc/qcom/socinfo.c +++ b/drivers/soc/qcom/socinfo.c @@ -4,6 +4,7 @@ * Copyright (c) 2017-2019, Linaro Ltd. */ +#include <linux/debugfs.h> #include <linux/err.h> #include <linux/module.h> #include <linux/platform_device.h> @@ -29,6 +30,28 @@ */ #define SMEM_HW_SW_BUILD_ID 137 +#ifdef CONFIG_DEBUG_FS +/* pmic model info */ +static const char *const pmic_model[] = { + [0] = "Unknown PMIC model", + [9] = "PM8994", + [11] = "PM8916", + [13] = "PM8058", + [14] = "PM8028", + [15] = "PM8901", + [16] = "PM8027", + [17] = "ISL9519", + [18] = "PM8921", + [19] = "PM8018", + [20] = "PM8015", + [21] = "PM8014", + [22] = "PM8821", + [23] = "PM8038", + [24] = "PM8922", + [25] = "PM8917", +}; +#endif /* CONFIG_DEBUG_FS */ + /* Socinfo SMEM item structure */ struct socinfo { __le32 fmt; @@ -70,6 +93,10 @@ struct socinfo { struct qcom_socinfo { struct soc_device *soc_dev; struct soc_device_attribute attr; +#ifdef CONFIG_DEBUG_FS + struct dentry *dbg_root; +#endif /* CONFIG_DEBUG_FS */ + struct socinfo *socinfo; }; struct soc_of_id { @@ -133,6 +160,171 @@ static const char *socinfo_machine(struct device *dev, unsigned int id) return NULL; } +#ifdef CONFIG_DEBUG_FS + +#define UINT_SHOW(name, attr) \ +static int qcom_show_##name(struct seq_file *seq, void *p) \ +{ \ + struct socinfo *socinfo = seq->private; \ + seq_printf(seq, "%u\n", le32_to_cpu(socinfo->attr)); \ + return 0; \ +} \ +static int qcom_open_##name(struct inode *inode, struct file *file) \ +{ \ + return single_open(file, qcom_show_##name, inode->i_private); \ +} \ + \ +static const struct file_operations qcom_ ##name## _ops = { \ + .open = qcom_open_##name, \ + .read = seq_read, \ + .llseek = seq_lseek, \ + .release = single_release, \ +} + +#define DEBUGFS_UINT_ADD(name) \ + debugfs_create_file(__stringify(name), 0400, \ + qcom_socinfo->dbg_root, \ + qcom_socinfo->socinfo, &qcom_ ##name## _ops) + +#define HEX_SHOW(name, attr) \ +static int qcom_show_##name(struct seq_file *seq, void *p) \ +{ \ + struct socinfo *socinfo = seq->private; \ + seq_printf(seq, "0x%x\n", le32_to_cpu(socinfo->attr)); \ + return 0; \ +} \ +static int qcom_open_##name(struct inode *inode, struct file *file) \ +{ \ + return single_open(file, qcom_show_##name, inode->i_private); \ +} \ + \ +static const struct file_operations qcom_ ##name## _ops = { \ + .open = qcom_open_##name, \ + .read = seq_read, \ + .llseek = seq_lseek, \ + .release = single_release, \ +} + +#define DEBUGFS_HEX_ADD(name) \ + debugfs_create_file(__stringify(name), 0400, \ + qcom_socinfo->dbg_root, \ + qcom_socinfo->socinfo, &qcom_ ##name## _ops) + + +#define QCOM_OPEN(name, _func) \ +static int qcom_open_##name(struct inode *inode, struct file *file) \ +{ \ + return single_open(file, _func, inode->i_private); \ +} \ + \ +static const struct file_operations qcom_ ##name## _ops = { \ + .open = qcom_open_##name, \ + .read = seq_read, \ + .llseek = seq_lseek, \ + .release = single_release, \ +} + +#define DEBUGFS_ADD(name) \ + debugfs_create_file(__stringify(name), 0400, \ + qcom_socinfo->dbg_root, \ + qcom_socinfo->socinfo, &qcom_ ##name## _ops) + + +static int qcom_show_build_id(struct seq_file *seq, void *p) +{ + struct socinfo *socinfo = seq->private; + + seq_printf(seq, "%s\n", socinfo->build_id); + + return 0; +} + +static int qcom_show_accessory_chip(struct seq_file *seq, void *p) +{ + struct socinfo *socinfo = seq->private; + + seq_printf(seq, "%d\n", le32_to_cpu(socinfo->accessory_chip)); + + return 0; +} + +static int qcom_show_platform_subtype(struct seq_file *seq, void *p) +{ + struct socinfo *socinfo = seq->private; + int subtype = le32_to_cpu(socinfo->hw_plat_subtype); + + if (subtype < 0) + return -EINVAL; + + seq_printf(seq, "%u\n", subtype); + + return 0; +} + +static int qcom_show_pmic_model(struct seq_file *seq, void *p) +{ + struct socinfo *socinfo = seq->private; + int model = SOCINFO_MINOR(le32_to_cpu(socinfo->pmic_model)); + + if (model < 0) + return -EINVAL; + + seq_printf(seq, "%s\n", pmic_model[model]); + + return 0; +} + +static int qcom_show_pmic_die_revision(struct seq_file *seq, void *p) +{ + struct socinfo *socinfo = seq->private; + + seq_printf(seq, "%u.%u\n", + SOCINFO_MAJOR(le32_to_cpu(socinfo->pmic_die_rev)), + SOCINFO_MINOR(le32_to_cpu(socinfo->pmic_die_rev))); + + return 0; +} + +UINT_SHOW(raw_version, raw_ver); +UINT_SHOW(hardware_platform, hw_plat); +UINT_SHOW(platform_version, plat_ver); +UINT_SHOW(foundry_id, foundry_id); +HEX_SHOW(chip_family, chip_family); +HEX_SHOW(raw_device_family, raw_device_family); +HEX_SHOW(raw_device_number, raw_device_num); +QCOM_OPEN(build_id, qcom_show_build_id); +QCOM_OPEN(accessory_chip, qcom_show_accessory_chip); +QCOM_OPEN(pmic_model, qcom_show_pmic_model); +QCOM_OPEN(platform_subtype, qcom_show_platform_subtype); +QCOM_OPEN(pmic_die_revision, qcom_show_pmic_die_revision); + +static void socinfo_debugfs_init(struct qcom_socinfo *qcom_socinfo) +{ + qcom_socinfo->dbg_root = debugfs_create_dir("qcom_socinfo", NULL); + + DEBUGFS_UINT_ADD(raw_version); + DEBUGFS_UINT_ADD(hardware_platform); + DEBUGFS_UINT_ADD(platform_version); + DEBUGFS_UINT_ADD(foundry_id); + DEBUGFS_HEX_ADD(chip_family); + DEBUGFS_HEX_ADD(raw_device_family); + DEBUGFS_HEX_ADD(raw_device_number); + DEBUGFS_ADD(build_id); + DEBUGFS_ADD(accessory_chip); + DEBUGFS_ADD(pmic_model); + DEBUGFS_ADD(platform_subtype); + DEBUGFS_ADD(pmic_die_revision); +} + +static void socinfo_debugfs_exit(struct qcom_socinfo *qcom_socinfo) +{ + debugfs_remove_recursive(qcom_socinfo->dbg_root); +} +#else +static void socinfo_debugfs_init(struct qcom_socinfo *qcom_socinfo) { return 0; } +static void socinfo_debugfs_exit(struct qcom_socinfo *qcom_socinfo) { } +#endif /* CONFIG_DEBUG_FS */ + static int qcom_socinfo_probe(struct platform_device *pdev) { struct qcom_socinfo *qs; @@ -165,6 +357,10 @@ static int qcom_socinfo_probe(struct platform_device *pdev) if (IS_ERR(qs->soc_dev)) return PTR_ERR(qs->soc_dev); + qs->socinfo = info; + + socinfo_debugfs_init(qs); + /* Feed the soc specific unique data into entropy pool */ add_device_randomness(info, item_size); @@ -179,6 +375,8 @@ static int qcom_socinfo_remove(struct platform_device *pdev) soc_device_unregister(qs->soc_dev); + socinfo_debugfs_exit(qs); + return 0; } -- 2.17.1 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v2 3/5] soc: qcom: socinfo: Expose custom attributes 2019-02-20 4:58 [PATCH v2 3/5] soc: qcom: socinfo: Expose custom attributes Vaishali Thakkar @ 2019-02-21 12:18 ` Laurent Pinchart 2019-02-21 15:57 ` Bjorn Andersson 0 siblings, 1 reply; 8+ messages in thread From: Laurent Pinchart @ 2019-02-21 12:18 UTC (permalink / raw) To: Vaishali Thakkar Cc: andy.gross, david.brown, gregkh, linux-arm-msm, linux-kernel, rafael, bjorn.andersson, vkoul Hi Vaishali, Thank you for the patch. On Wed, Feb 20, 2019 at 10:28:29AM +0530, Vaishali Thakkar wrote: > The Qualcomm socinfo provides a number of additional attributes, > add these to the socinfo driver and expose them via debugfs > functionality. What is the use case for these attributes ? I fear they will be used in production systems, and that would require debugfs in production, which isn't a good idea. If you need to expose those attributes for anything else than debugging then we need a proper API, likely sysfs-based. > Signed-off-by: Vaishali Thakkar <vaishali.thakkar@linaro.org> > --- > Changes since v1: > - Remove unnecessary debugfs dir creation check > - Align ifdefs to left > - Fix function signatures for debugfs init/exit > --- > drivers/soc/qcom/socinfo.c | 198 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 198 insertions(+) > > diff --git a/drivers/soc/qcom/socinfo.c b/drivers/soc/qcom/socinfo.c > index 02078049fac7..5f4bef216ae1 100644 > --- a/drivers/soc/qcom/socinfo.c > +++ b/drivers/soc/qcom/socinfo.c > @@ -4,6 +4,7 @@ > * Copyright (c) 2017-2019, Linaro Ltd. > */ > > +#include <linux/debugfs.h> > #include <linux/err.h> > #include <linux/module.h> > #include <linux/platform_device.h> > @@ -29,6 +30,28 @@ > */ > #define SMEM_HW_SW_BUILD_ID 137 > > +#ifdef CONFIG_DEBUG_FS > +/* pmic model info */ > +static const char *const pmic_model[] = { > + [0] = "Unknown PMIC model", > + [9] = "PM8994", > + [11] = "PM8916", > + [13] = "PM8058", > + [14] = "PM8028", > + [15] = "PM8901", > + [16] = "PM8027", > + [17] = "ISL9519", > + [18] = "PM8921", > + [19] = "PM8018", > + [20] = "PM8015", > + [21] = "PM8014", > + [22] = "PM8821", > + [23] = "PM8038", > + [24] = "PM8922", > + [25] = "PM8917", > +}; > +#endif /* CONFIG_DEBUG_FS */ > + > /* Socinfo SMEM item structure */ > struct socinfo { > __le32 fmt; > @@ -70,6 +93,10 @@ struct socinfo { > struct qcom_socinfo { > struct soc_device *soc_dev; > struct soc_device_attribute attr; > +#ifdef CONFIG_DEBUG_FS > + struct dentry *dbg_root; > +#endif /* CONFIG_DEBUG_FS */ > + struct socinfo *socinfo; > }; > > struct soc_of_id { > @@ -133,6 +160,171 @@ static const char *socinfo_machine(struct device *dev, unsigned int id) > return NULL; > } > > +#ifdef CONFIG_DEBUG_FS > + > +#define UINT_SHOW(name, attr) \ > +static int qcom_show_##name(struct seq_file *seq, void *p) \ > +{ \ > + struct socinfo *socinfo = seq->private; \ > + seq_printf(seq, "%u\n", le32_to_cpu(socinfo->attr)); \ > + return 0; \ > +} \ > +static int qcom_open_##name(struct inode *inode, struct file *file) \ > +{ \ > + return single_open(file, qcom_show_##name, inode->i_private); \ > +} \ > + \ > +static const struct file_operations qcom_ ##name## _ops = { \ > + .open = qcom_open_##name, \ > + .read = seq_read, \ > + .llseek = seq_lseek, \ > + .release = single_release, \ > +} > + > +#define DEBUGFS_UINT_ADD(name) \ > + debugfs_create_file(__stringify(name), 0400, \ > + qcom_socinfo->dbg_root, \ > + qcom_socinfo->socinfo, &qcom_ ##name## _ops) > + > +#define HEX_SHOW(name, attr) \ > +static int qcom_show_##name(struct seq_file *seq, void *p) \ > +{ \ > + struct socinfo *socinfo = seq->private; \ > + seq_printf(seq, "0x%x\n", le32_to_cpu(socinfo->attr)); \ > + return 0; \ > +} \ > +static int qcom_open_##name(struct inode *inode, struct file *file) \ > +{ \ > + return single_open(file, qcom_show_##name, inode->i_private); \ > +} \ > + \ > +static const struct file_operations qcom_ ##name## _ops = { \ > + .open = qcom_open_##name, \ > + .read = seq_read, \ > + .llseek = seq_lseek, \ > + .release = single_release, \ > +} > + > +#define DEBUGFS_HEX_ADD(name) \ > + debugfs_create_file(__stringify(name), 0400, \ > + qcom_socinfo->dbg_root, \ > + qcom_socinfo->socinfo, &qcom_ ##name## _ops) > + > + > +#define QCOM_OPEN(name, _func) \ > +static int qcom_open_##name(struct inode *inode, struct file *file) \ > +{ \ > + return single_open(file, _func, inode->i_private); \ > +} \ > + \ > +static const struct file_operations qcom_ ##name## _ops = { \ > + .open = qcom_open_##name, \ > + .read = seq_read, \ > + .llseek = seq_lseek, \ > + .release = single_release, \ > +} > + > +#define DEBUGFS_ADD(name) \ > + debugfs_create_file(__stringify(name), 0400, \ > + qcom_socinfo->dbg_root, \ > + qcom_socinfo->socinfo, &qcom_ ##name## _ops) > + > + > +static int qcom_show_build_id(struct seq_file *seq, void *p) > +{ > + struct socinfo *socinfo = seq->private; > + > + seq_printf(seq, "%s\n", socinfo->build_id); > + > + return 0; > +} > + > +static int qcom_show_accessory_chip(struct seq_file *seq, void *p) > +{ > + struct socinfo *socinfo = seq->private; > + > + seq_printf(seq, "%d\n", le32_to_cpu(socinfo->accessory_chip)); > + > + return 0; > +} > + > +static int qcom_show_platform_subtype(struct seq_file *seq, void *p) > +{ > + struct socinfo *socinfo = seq->private; > + int subtype = le32_to_cpu(socinfo->hw_plat_subtype); > + > + if (subtype < 0) > + return -EINVAL; > + > + seq_printf(seq, "%u\n", subtype); > + > + return 0; > +} > + > +static int qcom_show_pmic_model(struct seq_file *seq, void *p) > +{ > + struct socinfo *socinfo = seq->private; > + int model = SOCINFO_MINOR(le32_to_cpu(socinfo->pmic_model)); > + > + if (model < 0) > + return -EINVAL; > + > + seq_printf(seq, "%s\n", pmic_model[model]); > + > + return 0; > +} > + > +static int qcom_show_pmic_die_revision(struct seq_file *seq, void *p) > +{ > + struct socinfo *socinfo = seq->private; > + > + seq_printf(seq, "%u.%u\n", > + SOCINFO_MAJOR(le32_to_cpu(socinfo->pmic_die_rev)), > + SOCINFO_MINOR(le32_to_cpu(socinfo->pmic_die_rev))); > + > + return 0; > +} > + > +UINT_SHOW(raw_version, raw_ver); > +UINT_SHOW(hardware_platform, hw_plat); > +UINT_SHOW(platform_version, plat_ver); > +UINT_SHOW(foundry_id, foundry_id); > +HEX_SHOW(chip_family, chip_family); > +HEX_SHOW(raw_device_family, raw_device_family); > +HEX_SHOW(raw_device_number, raw_device_num); > +QCOM_OPEN(build_id, qcom_show_build_id); > +QCOM_OPEN(accessory_chip, qcom_show_accessory_chip); > +QCOM_OPEN(pmic_model, qcom_show_pmic_model); > +QCOM_OPEN(platform_subtype, qcom_show_platform_subtype); > +QCOM_OPEN(pmic_die_revision, qcom_show_pmic_die_revision); > + > +static void socinfo_debugfs_init(struct qcom_socinfo *qcom_socinfo) > +{ > + qcom_socinfo->dbg_root = debugfs_create_dir("qcom_socinfo", NULL); > + > + DEBUGFS_UINT_ADD(raw_version); > + DEBUGFS_UINT_ADD(hardware_platform); > + DEBUGFS_UINT_ADD(platform_version); > + DEBUGFS_UINT_ADD(foundry_id); > + DEBUGFS_HEX_ADD(chip_family); > + DEBUGFS_HEX_ADD(raw_device_family); > + DEBUGFS_HEX_ADD(raw_device_number); > + DEBUGFS_ADD(build_id); > + DEBUGFS_ADD(accessory_chip); > + DEBUGFS_ADD(pmic_model); > + DEBUGFS_ADD(platform_subtype); > + DEBUGFS_ADD(pmic_die_revision); > +} > + > +static void socinfo_debugfs_exit(struct qcom_socinfo *qcom_socinfo) > +{ > + debugfs_remove_recursive(qcom_socinfo->dbg_root); > +} > +#else > +static void socinfo_debugfs_init(struct qcom_socinfo *qcom_socinfo) { return 0; } > +static void socinfo_debugfs_exit(struct qcom_socinfo *qcom_socinfo) { } > +#endif /* CONFIG_DEBUG_FS */ > + > static int qcom_socinfo_probe(struct platform_device *pdev) > { > struct qcom_socinfo *qs; > @@ -165,6 +357,10 @@ static int qcom_socinfo_probe(struct platform_device *pdev) > if (IS_ERR(qs->soc_dev)) > return PTR_ERR(qs->soc_dev); > > + qs->socinfo = info; > + > + socinfo_debugfs_init(qs); > + > /* Feed the soc specific unique data into entropy pool */ > add_device_randomness(info, item_size); > > @@ -179,6 +375,8 @@ static int qcom_socinfo_remove(struct platform_device *pdev) > > soc_device_unregister(qs->soc_dev); > > + socinfo_debugfs_exit(qs); > + > return 0; > } > -- Regards, Laurent Pinchart ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2 3/5] soc: qcom: socinfo: Expose custom attributes 2019-02-21 12:18 ` Laurent Pinchart @ 2019-02-21 15:57 ` Bjorn Andersson 2019-02-21 22:13 ` Laurent Pinchart 2019-02-22 11:54 ` Marc Gonzalez 0 siblings, 2 replies; 8+ messages in thread From: Bjorn Andersson @ 2019-02-21 15:57 UTC (permalink / raw) To: Laurent Pinchart Cc: Vaishali Thakkar, andy.gross, david.brown, gregkh, linux-arm-msm, linux-kernel, rafael, vkoul On Thu 21 Feb 04:18 PST 2019, Laurent Pinchart wrote: > Hi Vaishali, > > Thank you for the patch. > > On Wed, Feb 20, 2019 at 10:28:29AM +0530, Vaishali Thakkar wrote: > > The Qualcomm socinfo provides a number of additional attributes, > > add these to the socinfo driver and expose them via debugfs > > functionality. > > What is the use case for these attributes ? I fear they will be used in > production systems, and that would require debugfs in production, which > isn't a good idea. If you need to expose those attributes for anything > else than debugging then we need a proper API, likely sysfs-based. > The use case of these attributes, beyond development/debugging, are unfortunately somewhat unknown and is the reason why they where moved to debugfs from the earlier attempts to upstream this. I think the production requirements at hand prohibits debugfs to be present, so attributes that are required beyond development/debugging purposes would have to be migrated out to sysfs - but the idea here is that such migration would have come with the missing motivation to add them there today. Regards, Bjorn > > Signed-off-by: Vaishali Thakkar <vaishali.thakkar@linaro.org> > > --- > > Changes since v1: > > - Remove unnecessary debugfs dir creation check > > - Align ifdefs to left > > - Fix function signatures for debugfs init/exit > > --- > > drivers/soc/qcom/socinfo.c | 198 +++++++++++++++++++++++++++++++++++++ > > 1 file changed, 198 insertions(+) > > > > diff --git a/drivers/soc/qcom/socinfo.c b/drivers/soc/qcom/socinfo.c > > index 02078049fac7..5f4bef216ae1 100644 > > --- a/drivers/soc/qcom/socinfo.c > > +++ b/drivers/soc/qcom/socinfo.c > > @@ -4,6 +4,7 @@ > > * Copyright (c) 2017-2019, Linaro Ltd. > > */ > > > > +#include <linux/debugfs.h> > > #include <linux/err.h> > > #include <linux/module.h> > > #include <linux/platform_device.h> > > @@ -29,6 +30,28 @@ > > */ > > #define SMEM_HW_SW_BUILD_ID 137 > > > > +#ifdef CONFIG_DEBUG_FS > > +/* pmic model info */ > > +static const char *const pmic_model[] = { > > + [0] = "Unknown PMIC model", > > + [9] = "PM8994", > > + [11] = "PM8916", > > + [13] = "PM8058", > > + [14] = "PM8028", > > + [15] = "PM8901", > > + [16] = "PM8027", > > + [17] = "ISL9519", > > + [18] = "PM8921", > > + [19] = "PM8018", > > + [20] = "PM8015", > > + [21] = "PM8014", > > + [22] = "PM8821", > > + [23] = "PM8038", > > + [24] = "PM8922", > > + [25] = "PM8917", > > +}; > > +#endif /* CONFIG_DEBUG_FS */ > > + > > /* Socinfo SMEM item structure */ > > struct socinfo { > > __le32 fmt; > > @@ -70,6 +93,10 @@ struct socinfo { > > struct qcom_socinfo { > > struct soc_device *soc_dev; > > struct soc_device_attribute attr; > > +#ifdef CONFIG_DEBUG_FS > > + struct dentry *dbg_root; > > +#endif /* CONFIG_DEBUG_FS */ > > + struct socinfo *socinfo; > > }; > > > > struct soc_of_id { > > @@ -133,6 +160,171 @@ static const char *socinfo_machine(struct device *dev, unsigned int id) > > return NULL; > > } > > > > +#ifdef CONFIG_DEBUG_FS > > + > > +#define UINT_SHOW(name, attr) \ > > +static int qcom_show_##name(struct seq_file *seq, void *p) \ > > +{ \ > > + struct socinfo *socinfo = seq->private; \ > > + seq_printf(seq, "%u\n", le32_to_cpu(socinfo->attr)); \ > > + return 0; \ > > +} \ > > +static int qcom_open_##name(struct inode *inode, struct file *file) \ > > +{ \ > > + return single_open(file, qcom_show_##name, inode->i_private); \ > > +} \ > > + \ > > +static const struct file_operations qcom_ ##name## _ops = { \ > > + .open = qcom_open_##name, \ > > + .read = seq_read, \ > > + .llseek = seq_lseek, \ > > + .release = single_release, \ > > +} > > + > > +#define DEBUGFS_UINT_ADD(name) \ > > + debugfs_create_file(__stringify(name), 0400, \ > > + qcom_socinfo->dbg_root, \ > > + qcom_socinfo->socinfo, &qcom_ ##name## _ops) > > + > > +#define HEX_SHOW(name, attr) \ > > +static int qcom_show_##name(struct seq_file *seq, void *p) \ > > +{ \ > > + struct socinfo *socinfo = seq->private; \ > > + seq_printf(seq, "0x%x\n", le32_to_cpu(socinfo->attr)); \ > > + return 0; \ > > +} \ > > +static int qcom_open_##name(struct inode *inode, struct file *file) \ > > +{ \ > > + return single_open(file, qcom_show_##name, inode->i_private); \ > > +} \ > > + \ > > +static const struct file_operations qcom_ ##name## _ops = { \ > > + .open = qcom_open_##name, \ > > + .read = seq_read, \ > > + .llseek = seq_lseek, \ > > + .release = single_release, \ > > +} > > + > > +#define DEBUGFS_HEX_ADD(name) \ > > + debugfs_create_file(__stringify(name), 0400, \ > > + qcom_socinfo->dbg_root, \ > > + qcom_socinfo->socinfo, &qcom_ ##name## _ops) > > + > > + > > +#define QCOM_OPEN(name, _func) \ > > +static int qcom_open_##name(struct inode *inode, struct file *file) \ > > +{ \ > > + return single_open(file, _func, inode->i_private); \ > > +} \ > > + \ > > +static const struct file_operations qcom_ ##name## _ops = { \ > > + .open = qcom_open_##name, \ > > + .read = seq_read, \ > > + .llseek = seq_lseek, \ > > + .release = single_release, \ > > +} > > + > > +#define DEBUGFS_ADD(name) \ > > + debugfs_create_file(__stringify(name), 0400, \ > > + qcom_socinfo->dbg_root, \ > > + qcom_socinfo->socinfo, &qcom_ ##name## _ops) > > + > > + > > +static int qcom_show_build_id(struct seq_file *seq, void *p) > > +{ > > + struct socinfo *socinfo = seq->private; > > + > > + seq_printf(seq, "%s\n", socinfo->build_id); > > + > > + return 0; > > +} > > + > > +static int qcom_show_accessory_chip(struct seq_file *seq, void *p) > > +{ > > + struct socinfo *socinfo = seq->private; > > + > > + seq_printf(seq, "%d\n", le32_to_cpu(socinfo->accessory_chip)); > > + > > + return 0; > > +} > > + > > +static int qcom_show_platform_subtype(struct seq_file *seq, void *p) > > +{ > > + struct socinfo *socinfo = seq->private; > > + int subtype = le32_to_cpu(socinfo->hw_plat_subtype); > > + > > + if (subtype < 0) > > + return -EINVAL; > > + > > + seq_printf(seq, "%u\n", subtype); > > + > > + return 0; > > +} > > + > > +static int qcom_show_pmic_model(struct seq_file *seq, void *p) > > +{ > > + struct socinfo *socinfo = seq->private; > > + int model = SOCINFO_MINOR(le32_to_cpu(socinfo->pmic_model)); > > + > > + if (model < 0) > > + return -EINVAL; > > + > > + seq_printf(seq, "%s\n", pmic_model[model]); > > + > > + return 0; > > +} > > + > > +static int qcom_show_pmic_die_revision(struct seq_file *seq, void *p) > > +{ > > + struct socinfo *socinfo = seq->private; > > + > > + seq_printf(seq, "%u.%u\n", > > + SOCINFO_MAJOR(le32_to_cpu(socinfo->pmic_die_rev)), > > + SOCINFO_MINOR(le32_to_cpu(socinfo->pmic_die_rev))); > > + > > + return 0; > > +} > > + > > +UINT_SHOW(raw_version, raw_ver); > > +UINT_SHOW(hardware_platform, hw_plat); > > +UINT_SHOW(platform_version, plat_ver); > > +UINT_SHOW(foundry_id, foundry_id); > > +HEX_SHOW(chip_family, chip_family); > > +HEX_SHOW(raw_device_family, raw_device_family); > > +HEX_SHOW(raw_device_number, raw_device_num); > > +QCOM_OPEN(build_id, qcom_show_build_id); > > +QCOM_OPEN(accessory_chip, qcom_show_accessory_chip); > > +QCOM_OPEN(pmic_model, qcom_show_pmic_model); > > +QCOM_OPEN(platform_subtype, qcom_show_platform_subtype); > > +QCOM_OPEN(pmic_die_revision, qcom_show_pmic_die_revision); > > + > > +static void socinfo_debugfs_init(struct qcom_socinfo *qcom_socinfo) > > +{ > > + qcom_socinfo->dbg_root = debugfs_create_dir("qcom_socinfo", NULL); > > + > > + DEBUGFS_UINT_ADD(raw_version); > > + DEBUGFS_UINT_ADD(hardware_platform); > > + DEBUGFS_UINT_ADD(platform_version); > > + DEBUGFS_UINT_ADD(foundry_id); > > + DEBUGFS_HEX_ADD(chip_family); > > + DEBUGFS_HEX_ADD(raw_device_family); > > + DEBUGFS_HEX_ADD(raw_device_number); > > + DEBUGFS_ADD(build_id); > > + DEBUGFS_ADD(accessory_chip); > > + DEBUGFS_ADD(pmic_model); > > + DEBUGFS_ADD(platform_subtype); > > + DEBUGFS_ADD(pmic_die_revision); > > +} > > + > > +static void socinfo_debugfs_exit(struct qcom_socinfo *qcom_socinfo) > > +{ > > + debugfs_remove_recursive(qcom_socinfo->dbg_root); > > +} > > +#else > > +static void socinfo_debugfs_init(struct qcom_socinfo *qcom_socinfo) { return 0; } > > +static void socinfo_debugfs_exit(struct qcom_socinfo *qcom_socinfo) { } > > +#endif /* CONFIG_DEBUG_FS */ > > + > > static int qcom_socinfo_probe(struct platform_device *pdev) > > { > > struct qcom_socinfo *qs; > > @@ -165,6 +357,10 @@ static int qcom_socinfo_probe(struct platform_device *pdev) > > if (IS_ERR(qs->soc_dev)) > > return PTR_ERR(qs->soc_dev); > > > > + qs->socinfo = info; > > + > > + socinfo_debugfs_init(qs); > > + > > /* Feed the soc specific unique data into entropy pool */ > > add_device_randomness(info, item_size); > > > > @@ -179,6 +375,8 @@ static int qcom_socinfo_remove(struct platform_device *pdev) > > > > soc_device_unregister(qs->soc_dev); > > > > + socinfo_debugfs_exit(qs); > > + > > return 0; > > } > > > > -- > Regards, > > Laurent Pinchart ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2 3/5] soc: qcom: socinfo: Expose custom attributes 2019-02-21 15:57 ` Bjorn Andersson @ 2019-02-21 22:13 ` Laurent Pinchart 2019-02-22 7:16 ` Greg KH 2019-02-22 11:54 ` Marc Gonzalez 1 sibling, 1 reply; 8+ messages in thread From: Laurent Pinchart @ 2019-02-21 22:13 UTC (permalink / raw) To: Bjorn Andersson Cc: Vaishali Thakkar, andy.gross, david.brown, gregkh, linux-arm-msm, linux-kernel, rafael, vkoul Hi Bjorn, On Thu, Feb 21, 2019 at 07:57:42AM -0800, Bjorn Andersson wrote: > On Thu 21 Feb 04:18 PST 2019, Laurent Pinchart wrote: > > > Hi Vaishali, > > > > Thank you for the patch. > > > > On Wed, Feb 20, 2019 at 10:28:29AM +0530, Vaishali Thakkar wrote: > > > The Qualcomm socinfo provides a number of additional attributes, > > > add these to the socinfo driver and expose them via debugfs > > > functionality. > > > > What is the use case for these attributes ? I fear they will be used in > > production systems, and that would require debugfs in production, which > > isn't a good idea. If you need to expose those attributes for anything > > else than debugging then we need a proper API, likely sysfs-based. > > The use case of these attributes, beyond development/debugging, are > unfortunately somewhat unknown and is the reason why they where moved to > debugfs from the earlier attempts to upstream this. > > I think the production requirements at hand prohibits debugfs to be > present, so attributes that are required beyond development/debugging > purposes would have to be migrated out to sysfs - but the idea here is > that such migration would have come with the missing motivation to add > them there today. If the use case is just debug/development, would it be enough to print this information in the kernel log at boot time ? I may be a bit paranoid, but I always worry about API abuse :-( > > > Signed-off-by: Vaishali Thakkar <vaishali.thakkar@linaro.org> > > > --- > > > Changes since v1: > > > - Remove unnecessary debugfs dir creation check > > > - Align ifdefs to left > > > - Fix function signatures for debugfs init/exit > > > --- > > > drivers/soc/qcom/socinfo.c | 198 +++++++++++++++++++++++++++++++++++++ > > > 1 file changed, 198 insertions(+) > > > > > > diff --git a/drivers/soc/qcom/socinfo.c b/drivers/soc/qcom/socinfo.c > > > index 02078049fac7..5f4bef216ae1 100644 > > > --- a/drivers/soc/qcom/socinfo.c > > > +++ b/drivers/soc/qcom/socinfo.c > > > @@ -4,6 +4,7 @@ > > > * Copyright (c) 2017-2019, Linaro Ltd. > > > */ > > > > > > +#include <linux/debugfs.h> > > > #include <linux/err.h> > > > #include <linux/module.h> > > > #include <linux/platform_device.h> > > > @@ -29,6 +30,28 @@ > > > */ > > > #define SMEM_HW_SW_BUILD_ID 137 > > > > > > +#ifdef CONFIG_DEBUG_FS > > > +/* pmic model info */ > > > +static const char *const pmic_model[] = { > > > + [0] = "Unknown PMIC model", > > > + [9] = "PM8994", > > > + [11] = "PM8916", > > > + [13] = "PM8058", > > > + [14] = "PM8028", > > > + [15] = "PM8901", > > > + [16] = "PM8027", > > > + [17] = "ISL9519", > > > + [18] = "PM8921", > > > + [19] = "PM8018", > > > + [20] = "PM8015", > > > + [21] = "PM8014", > > > + [22] = "PM8821", > > > + [23] = "PM8038", > > > + [24] = "PM8922", > > > + [25] = "PM8917", > > > +}; > > > +#endif /* CONFIG_DEBUG_FS */ > > > + > > > /* Socinfo SMEM item structure */ > > > struct socinfo { > > > __le32 fmt; > > > @@ -70,6 +93,10 @@ struct socinfo { > > > struct qcom_socinfo { > > > struct soc_device *soc_dev; > > > struct soc_device_attribute attr; > > > +#ifdef CONFIG_DEBUG_FS > > > + struct dentry *dbg_root; > > > +#endif /* CONFIG_DEBUG_FS */ > > > + struct socinfo *socinfo; > > > }; > > > > > > struct soc_of_id { > > > @@ -133,6 +160,171 @@ static const char *socinfo_machine(struct device *dev, unsigned int id) > > > return NULL; > > > } > > > > > > +#ifdef CONFIG_DEBUG_FS > > > + > > > +#define UINT_SHOW(name, attr) \ > > > +static int qcom_show_##name(struct seq_file *seq, void *p) \ > > > +{ \ > > > + struct socinfo *socinfo = seq->private; \ > > > + seq_printf(seq, "%u\n", le32_to_cpu(socinfo->attr)); \ > > > + return 0; \ > > > +} \ > > > +static int qcom_open_##name(struct inode *inode, struct file *file) \ > > > +{ \ > > > + return single_open(file, qcom_show_##name, inode->i_private); \ > > > +} \ > > > + \ > > > +static const struct file_operations qcom_ ##name## _ops = { \ > > > + .open = qcom_open_##name, \ > > > + .read = seq_read, \ > > > + .llseek = seq_lseek, \ > > > + .release = single_release, \ > > > +} > > > + > > > +#define DEBUGFS_UINT_ADD(name) \ > > > + debugfs_create_file(__stringify(name), 0400, \ > > > + qcom_socinfo->dbg_root, \ > > > + qcom_socinfo->socinfo, &qcom_ ##name## _ops) > > > + > > > +#define HEX_SHOW(name, attr) \ > > > +static int qcom_show_##name(struct seq_file *seq, void *p) \ > > > +{ \ > > > + struct socinfo *socinfo = seq->private; \ > > > + seq_printf(seq, "0x%x\n", le32_to_cpu(socinfo->attr)); \ > > > + return 0; \ > > > +} \ > > > +static int qcom_open_##name(struct inode *inode, struct file *file) \ > > > +{ \ > > > + return single_open(file, qcom_show_##name, inode->i_private); \ > > > +} \ > > > + \ > > > +static const struct file_operations qcom_ ##name## _ops = { \ > > > + .open = qcom_open_##name, \ > > > + .read = seq_read, \ > > > + .llseek = seq_lseek, \ > > > + .release = single_release, \ > > > +} > > > + > > > +#define DEBUGFS_HEX_ADD(name) \ > > > + debugfs_create_file(__stringify(name), 0400, \ > > > + qcom_socinfo->dbg_root, \ > > > + qcom_socinfo->socinfo, &qcom_ ##name## _ops) > > > + > > > + > > > +#define QCOM_OPEN(name, _func) \ > > > +static int qcom_open_##name(struct inode *inode, struct file *file) \ > > > +{ \ > > > + return single_open(file, _func, inode->i_private); \ > > > +} \ > > > + \ > > > +static const struct file_operations qcom_ ##name## _ops = { \ > > > + .open = qcom_open_##name, \ > > > + .read = seq_read, \ > > > + .llseek = seq_lseek, \ > > > + .release = single_release, \ > > > +} > > > + > > > +#define DEBUGFS_ADD(name) \ > > > + debugfs_create_file(__stringify(name), 0400, \ > > > + qcom_socinfo->dbg_root, \ > > > + qcom_socinfo->socinfo, &qcom_ ##name## _ops) > > > + > > > + > > > +static int qcom_show_build_id(struct seq_file *seq, void *p) > > > +{ > > > + struct socinfo *socinfo = seq->private; > > > + > > > + seq_printf(seq, "%s\n", socinfo->build_id); > > > + > > > + return 0; > > > +} > > > + > > > +static int qcom_show_accessory_chip(struct seq_file *seq, void *p) > > > +{ > > > + struct socinfo *socinfo = seq->private; > > > + > > > + seq_printf(seq, "%d\n", le32_to_cpu(socinfo->accessory_chip)); > > > + > > > + return 0; > > > +} > > > + > > > +static int qcom_show_platform_subtype(struct seq_file *seq, void *p) > > > +{ > > > + struct socinfo *socinfo = seq->private; > > > + int subtype = le32_to_cpu(socinfo->hw_plat_subtype); > > > + > > > + if (subtype < 0) > > > + return -EINVAL; > > > + > > > + seq_printf(seq, "%u\n", subtype); > > > + > > > + return 0; > > > +} > > > + > > > +static int qcom_show_pmic_model(struct seq_file *seq, void *p) > > > +{ > > > + struct socinfo *socinfo = seq->private; > > > + int model = SOCINFO_MINOR(le32_to_cpu(socinfo->pmic_model)); > > > + > > > + if (model < 0) > > > + return -EINVAL; > > > + > > > + seq_printf(seq, "%s\n", pmic_model[model]); > > > + > > > + return 0; > > > +} > > > + > > > +static int qcom_show_pmic_die_revision(struct seq_file *seq, void *p) > > > +{ > > > + struct socinfo *socinfo = seq->private; > > > + > > > + seq_printf(seq, "%u.%u\n", > > > + SOCINFO_MAJOR(le32_to_cpu(socinfo->pmic_die_rev)), > > > + SOCINFO_MINOR(le32_to_cpu(socinfo->pmic_die_rev))); > > > + > > > + return 0; > > > +} > > > + > > > +UINT_SHOW(raw_version, raw_ver); > > > +UINT_SHOW(hardware_platform, hw_plat); > > > +UINT_SHOW(platform_version, plat_ver); > > > +UINT_SHOW(foundry_id, foundry_id); > > > +HEX_SHOW(chip_family, chip_family); > > > +HEX_SHOW(raw_device_family, raw_device_family); > > > +HEX_SHOW(raw_device_number, raw_device_num); > > > +QCOM_OPEN(build_id, qcom_show_build_id); > > > +QCOM_OPEN(accessory_chip, qcom_show_accessory_chip); > > > +QCOM_OPEN(pmic_model, qcom_show_pmic_model); > > > +QCOM_OPEN(platform_subtype, qcom_show_platform_subtype); > > > +QCOM_OPEN(pmic_die_revision, qcom_show_pmic_die_revision); > > > + > > > +static void socinfo_debugfs_init(struct qcom_socinfo *qcom_socinfo) > > > +{ > > > + qcom_socinfo->dbg_root = debugfs_create_dir("qcom_socinfo", NULL); > > > + > > > + DEBUGFS_UINT_ADD(raw_version); > > > + DEBUGFS_UINT_ADD(hardware_platform); > > > + DEBUGFS_UINT_ADD(platform_version); > > > + DEBUGFS_UINT_ADD(foundry_id); > > > + DEBUGFS_HEX_ADD(chip_family); > > > + DEBUGFS_HEX_ADD(raw_device_family); > > > + DEBUGFS_HEX_ADD(raw_device_number); > > > + DEBUGFS_ADD(build_id); > > > + DEBUGFS_ADD(accessory_chip); > > > + DEBUGFS_ADD(pmic_model); > > > + DEBUGFS_ADD(platform_subtype); > > > + DEBUGFS_ADD(pmic_die_revision); > > > +} > > > + > > > +static void socinfo_debugfs_exit(struct qcom_socinfo *qcom_socinfo) > > > +{ > > > + debugfs_remove_recursive(qcom_socinfo->dbg_root); > > > +} > > > +#else > > > +static void socinfo_debugfs_init(struct qcom_socinfo *qcom_socinfo) { return 0; } > > > +static void socinfo_debugfs_exit(struct qcom_socinfo *qcom_socinfo) { } > > > +#endif /* CONFIG_DEBUG_FS */ > > > + > > > static int qcom_socinfo_probe(struct platform_device *pdev) > > > { > > > struct qcom_socinfo *qs; > > > @@ -165,6 +357,10 @@ static int qcom_socinfo_probe(struct platform_device *pdev) > > > if (IS_ERR(qs->soc_dev)) > > > return PTR_ERR(qs->soc_dev); > > > > > > + qs->socinfo = info; > > > + > > > + socinfo_debugfs_init(qs); > > > + > > > /* Feed the soc specific unique data into entropy pool */ > > > add_device_randomness(info, item_size); > > > > > > @@ -179,6 +375,8 @@ static int qcom_socinfo_remove(struct platform_device *pdev) > > > > > > soc_device_unregister(qs->soc_dev); > > > > > > + socinfo_debugfs_exit(qs); > > > + > > > return 0; > > > } > > > -- Regards, Laurent Pinchart ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2 3/5] soc: qcom: socinfo: Expose custom attributes 2019-02-21 22:13 ` Laurent Pinchart @ 2019-02-22 7:16 ` Greg KH 2019-02-22 9:51 ` Laurent Pinchart 0 siblings, 1 reply; 8+ messages in thread From: Greg KH @ 2019-02-22 7:16 UTC (permalink / raw) To: Laurent Pinchart Cc: Bjorn Andersson, Vaishali Thakkar, andy.gross, david.brown, linux-arm-msm, linux-kernel, rafael, vkoul On Fri, Feb 22, 2019 at 12:13:59AM +0200, Laurent Pinchart wrote: > Hi Bjorn, > > On Thu, Feb 21, 2019 at 07:57:42AM -0800, Bjorn Andersson wrote: > > On Thu 21 Feb 04:18 PST 2019, Laurent Pinchart wrote: > > > > > Hi Vaishali, > > > > > > Thank you for the patch. > > > > > > On Wed, Feb 20, 2019 at 10:28:29AM +0530, Vaishali Thakkar wrote: > > > > The Qualcomm socinfo provides a number of additional attributes, > > > > add these to the socinfo driver and expose them via debugfs > > > > functionality. > > > > > > What is the use case for these attributes ? I fear they will be used in > > > production systems, and that would require debugfs in production, which > > > isn't a good idea. If you need to expose those attributes for anything > > > else than debugging then we need a proper API, likely sysfs-based. > > > > The use case of these attributes, beyond development/debugging, are > > unfortunately somewhat unknown and is the reason why they where moved to > > debugfs from the earlier attempts to upstream this. > > > > I think the production requirements at hand prohibits debugfs to be > > present, so attributes that are required beyond development/debugging > > purposes would have to be migrated out to sysfs - but the idea here is > > that such migration would have come with the missing motivation to add > > them there today. > > If the use case is just debug/development, would it be enough to print > this information in the kernel log at boot time ? I may be a bit > paranoid, but I always worry about API abuse :-( Putting stuff in debugfs should be fine. No system should ever rely on debugfs for a properly running system as it is being disabled on almost all "sane" systems (Android included). If a vendor relies on this information for a properly working system, then it does not belong in debugfs. thanks, greg k-h ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2 3/5] soc: qcom: socinfo: Expose custom attributes 2019-02-22 7:16 ` Greg KH @ 2019-02-22 9:51 ` Laurent Pinchart 2019-02-22 10:52 ` Greg KH 0 siblings, 1 reply; 8+ messages in thread From: Laurent Pinchart @ 2019-02-22 9:51 UTC (permalink / raw) To: Greg KH Cc: Bjorn Andersson, Vaishali Thakkar, andy.gross, david.brown, linux-arm-msm, linux-kernel, rafael, vkoul Hi Greg, On Fri, Feb 22, 2019 at 08:16:16AM +0100, Greg KH wrote: > On Fri, Feb 22, 2019 at 12:13:59AM +0200, Laurent Pinchart wrote: > > On Thu, Feb 21, 2019 at 07:57:42AM -0800, Bjorn Andersson wrote: > > > On Thu 21 Feb 04:18 PST 2019, Laurent Pinchart wrote: > > > > On Wed, Feb 20, 2019 at 10:28:29AM +0530, Vaishali Thakkar wrote: > > > > > The Qualcomm socinfo provides a number of additional attributes, > > > > > add these to the socinfo driver and expose them via debugfs > > > > > functionality. > > > > > > > > What is the use case for these attributes ? I fear they will be used in > > > > production systems, and that would require debugfs in production, which > > > > isn't a good idea. If you need to expose those attributes for anything > > > > else than debugging then we need a proper API, likely sysfs-based. > > > > > > The use case of these attributes, beyond development/debugging, are > > > unfortunately somewhat unknown and is the reason why they where moved to > > > debugfs from the earlier attempts to upstream this. > > > > > > I think the production requirements at hand prohibits debugfs to be > > > present, so attributes that are required beyond development/debugging > > > purposes would have to be migrated out to sysfs - but the idea here is > > > that such migration would have come with the missing motivation to add > > > them there today. > > > > If the use case is just debug/development, would it be enough to print > > this information in the kernel log at boot time ? I may be a bit > > paranoid, but I always worry about API abuse :-( > > Putting stuff in debugfs should be fine. No system should ever rely on > debugfs for a properly running system as it is being disabled on almost > all "sane" systems (Android included). If a vendor relies on this > information for a properly working system, then it does not belong in > debugfs. There's certainly no disagreement about that, my concern is about vendors who will enable debugfs to access information they need just because it's there. Do I assume correctly we can "break the debugfs ABI" in mainline by changing the format of the information if needed ? -- Regards, Laurent Pinchart ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2 3/5] soc: qcom: socinfo: Expose custom attributes 2019-02-22 9:51 ` Laurent Pinchart @ 2019-02-22 10:52 ` Greg KH 0 siblings, 0 replies; 8+ messages in thread From: Greg KH @ 2019-02-22 10:52 UTC (permalink / raw) To: Laurent Pinchart Cc: Bjorn Andersson, Vaishali Thakkar, andy.gross, david.brown, linux-arm-msm, linux-kernel, rafael, vkoul On Fri, Feb 22, 2019 at 11:51:45AM +0200, Laurent Pinchart wrote: > Hi Greg, > > On Fri, Feb 22, 2019 at 08:16:16AM +0100, Greg KH wrote: > > On Fri, Feb 22, 2019 at 12:13:59AM +0200, Laurent Pinchart wrote: > > > On Thu, Feb 21, 2019 at 07:57:42AM -0800, Bjorn Andersson wrote: > > > > On Thu 21 Feb 04:18 PST 2019, Laurent Pinchart wrote: > > > > > On Wed, Feb 20, 2019 at 10:28:29AM +0530, Vaishali Thakkar wrote: > > > > > > The Qualcomm socinfo provides a number of additional attributes, > > > > > > add these to the socinfo driver and expose them via debugfs > > > > > > functionality. > > > > > > > > > > What is the use case for these attributes ? I fear they will be used in > > > > > production systems, and that would require debugfs in production, which > > > > > isn't a good idea. If you need to expose those attributes for anything > > > > > else than debugging then we need a proper API, likely sysfs-based. > > > > > > > > The use case of these attributes, beyond development/debugging, are > > > > unfortunately somewhat unknown and is the reason why they where moved to > > > > debugfs from the earlier attempts to upstream this. > > > > > > > > I think the production requirements at hand prohibits debugfs to be > > > > present, so attributes that are required beyond development/debugging > > > > purposes would have to be migrated out to sysfs - but the idea here is > > > > that such migration would have come with the missing motivation to add > > > > them there today. > > > > > > If the use case is just debug/development, would it be enough to print > > > this information in the kernel log at boot time ? I may be a bit > > > paranoid, but I always worry about API abuse :-( > > > > Putting stuff in debugfs should be fine. No system should ever rely on > > debugfs for a properly running system as it is being disabled on almost > > all "sane" systems (Android included). If a vendor relies on this > > information for a properly working system, then it does not belong in > > debugfs. > > There's certainly no disagreement about that, my concern is about > vendors who will enable debugfs to access information they need just > because it's there. Then they run a huge risk of relying on it. > Do I assume correctly we can "break the debugfs ABI" in mainline by > changing the format of the information if needed ? Yes. The only "rule" of debugfs is that there is no rule :) Please, break it every-other release if you want, no userspace tools _should_ be relying on it.[1] thanks, greg k-h [1] Yes, I know Android currently relies on debugfs for a number of crash-dump type of things in ion and binder, but there is active work upstream in AOSP to remove that dependancy as no Android device should ever have debugfs mounted on a "normal" system for the security reasons alone. ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2 3/5] soc: qcom: socinfo: Expose custom attributes 2019-02-21 15:57 ` Bjorn Andersson 2019-02-21 22:13 ` Laurent Pinchart @ 2019-02-22 11:54 ` Marc Gonzalez 1 sibling, 0 replies; 8+ messages in thread From: Marc Gonzalez @ 2019-02-22 11:54 UTC (permalink / raw) To: Bjorn Andersson, Laurent Pinchart Cc: Vaishali Thakkar, Andy Gross, David Brown, Greg Kroah-Hartman, MSM, LKML, Vinod Koul On 21/02/2019 16:57, Bjorn Andersson wrote: > On Thu 21 Feb 04:18 PST 2019, Laurent Pinchart wrote: > >> On Wed, Feb 20, 2019 at 10:28:29AM +0530, Vaishali Thakkar wrote: >> >>> The Qualcomm socinfo provides a number of additional attributes, >>> add these to the socinfo driver and expose them via debugfs >>> functionality. >> >> What is the use case for these attributes ? I fear they will be used in >> production systems, and that would require debugfs in production, which >> isn't a good idea. If you need to expose those attributes for anything >> else than debugging then we need a proper API, likely sysfs-based. > > The use case of these attributes, beyond development/debugging, are > unfortunately somewhat unknown and is the reason why they where moved to > debugfs from the earlier attempts to upstream this. > > I think the production requirements at hand prohibits debugfs to be > present, so attributes that are required beyond development/debugging > purposes would have to be migrated out to sysfs - but the idea here is > that such migration would have come with the missing motivation to add > them there today. On a tangential note, I saw the following message when using PCIe: atl1c 0000:01:00.0: vpd r/w failed. This is likely a firmware bug on this device. Contact the card vendor for a firmware update pcilib: sysfs_read_vpd: read failed: Connection timed out Is this in any way related to custom attributes? Regards. ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2019-02-22 11:54 UTC | newest] Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2019-02-20 4:58 [PATCH v2 3/5] soc: qcom: socinfo: Expose custom attributes Vaishali Thakkar 2019-02-21 12:18 ` Laurent Pinchart 2019-02-21 15:57 ` Bjorn Andersson 2019-02-21 22:13 ` Laurent Pinchart 2019-02-22 7:16 ` Greg KH 2019-02-22 9:51 ` Laurent Pinchart 2019-02-22 10:52 ` Greg KH 2019-02-22 11:54 ` Marc Gonzalez
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