| Message ID | 20220908152449.35457-21-farbere@amazon.com |
|---|---|
| State | Accepted |
| Commit | a4dd0b80b461a4cf2238013a43ff1bd6077c8056 |
| Headers | show |
| Series | [v5,01/21] dt-bindings: hwmon: (mr75203) fix "intel,vm-map" property to be optional | expand |
On 9/8/2022 9:11 PM, Andy Shevchenko wrote: > On Thu, Sep 08, 2022 at 03:24:48PM +0000, Eliav Farber wrote: >> This change adds debugfs to read and write temperature sensor >> coefficients >> - g, h, j and cal5. >> >> The coefficients can vary between product and product, so it can be very >> useful to be able to modify them on the fly during the calibration >> process. >> >> e.g.: >> >> cat /sys/kernel/debug/940f23d0000.pvt/ts_coeff_cal5 >> 4096 >> >> echo 83000 > sys/kernel/debug/940f23d0000.pvt/ts_coeff_g > > ... > >> - Return j coefficient to use debugfs_create_file() instead of >> debugfs_create_u32() because j is signed. > > You can use > > DEFINE_DEBUGFS_ATTRIBUTE(ts_coeff_j, ts_coeff_j_get, ts_coeff_j_set, > "%lld\n"); > > which still makes code compact. I tried your suggestion to use DEFINE_DEBUGFS_ATTRIBUTE but I can't set j to be a negative value: root@alpine:~# cat /sys/kernel/debug/940f23d0000.pvt/ts_coeff_j 0 root@alpine:~# echo 100 > /sys/kernel/debug/940f23d0000.pvt/ts_coeff_j root@alpine:~# cat /sys/kernel/debug/940f23d0000.pvt/ts_coeff_j 100 root@alpine:~# echo -100 > /sys/kernel/debug/940f23d0000.pvt/ts_coeff_j sh: write error: Invalid argument This is the code I added: static int ts_coeff_j_set(void *data, u64 val) { struct pvt_device *pvt = data; pvt->ts_coeff.j = val; return 0; } static int ts_coeff_j_get(void *data, u64 *val) { struct pvt_device *pvt = data; *val = pvt->ts_coeff.j; return 0; } DEFINE_DEBUGFS_ATTRIBUTE(ts_coeff_j_fops, ts_coeff_j_get, ts_coeff_j_set, "%lld\n"); static void devm_pvt_ts_dbgfs_remove(void *data) { struct pvt_device *pvt = (struct pvt_device *)data; debugfs_remove_recursive(pvt->dbgfs_dir); pvt->dbgfs_dir = NULL; } static int pvt_ts_dbgfs_create(struct pvt_device *pvt, struct device *dev) { ... debugfs_create_file("ts_coeff_j", 0644, pvt->dbgfs_dir, pvt, &ts_coeff_j_fops); ... I'm using kernel 5.10.112. Can you please see if I'm did anything wrong? -- Thanks, Eliav
On Wed, Sep 14, 2022 at 07:26:36AM +0300, Farber, Eliav wrote: > On 9/13/2022 8:01 PM, Andy Shevchenko wrote: > > On Tue, Sep 13, 2022 at 05:40:16PM +0300, Farber, Eliav wrote: > > > On 9/13/2022 4:06 PM, Farber, Eliav wrote: ... > > > It seems like debugfs_attr_write() calls simple_attr_write() and it uses > > > kstrtoull(), which is why it fails when setting a negative value. > > > This is the same also in v6.0-rc5. > > > > > > debugfs_attr_read() on the other hand does show the correct value also > > > when j is negative. > > > > Which puzzles me since there is a few drivers that use %lld. > > Yeah, changing it to > > > > ret = sscanf(attr->set_buf, attr->fmt, &val); > > if (ret != 1) > > ret = -EINVAL; > > > > probably can fix that. Dunno if debugfs maintainer is okay with this. > > > > P.S. This needs revisiting all format strings to see if there are no > > additional > > characters, otherwise that needs to be addressed first, if feasible. > > I was thinking of making such a correction: > > - ret = kstrtoull(attr->set_buf, 0, &val); > + if (attr->set_buf[0] == '-') > + ret = kstrtoll(attr->set_buf, 0, &val); > + else > + ret = kstrtoull(attr->set_buf, 0, &val); > > and when I tested the change it worked, but then I noticed this commit: > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/fs/libfs.c?h=v6.0-rc5&id=488dac0c9237647e9b8f788b6a342595bfa40bda > > According to this, it previously used simple_strtoll() which supports > negative values, but was changed to use kstrtoull() to deliberately > return '-EINVAL' if it gets a negative value. > > So I’m not sure debugfs maintainers will be okay with a fix that > basically reverts the commit I mentioned. > Hence, what do you suggest to do with my commit? > Is it ok to leave it as it is today? Meanwhile asking is not a problem, at least we will know for sure. And yes, leave it as is, but point to the thread where you asking the clarification.
On Wed, Sep 14, 2022 at 12:32:47PM +0300, Andy Shevchenko wrote: > On Wed, Sep 14, 2022 at 07:26:36AM +0300, Farber, Eliav wrote: > > On 9/13/2022 8:01 PM, Andy Shevchenko wrote: > > > On Tue, Sep 13, 2022 at 05:40:16PM +0300, Farber, Eliav wrote: > > > > On 9/13/2022 4:06 PM, Farber, Eliav wrote: ... > > > > It seems like debugfs_attr_write() calls simple_attr_write() and it uses > > > > kstrtoull(), which is why it fails when setting a negative value. > > > > This is the same also in v6.0-rc5. > > > > > > > > debugfs_attr_read() on the other hand does show the correct value also > > > > when j is negative. > > > > > > Which puzzles me since there is a few drivers that use %lld. > > > Yeah, changing it to > > > > > > ret = sscanf(attr->set_buf, attr->fmt, &val); > > > if (ret != 1) > > > ret = -EINVAL; > > > > > > probably can fix that. Dunno if debugfs maintainer is okay with this. > > > > > > P.S. This needs revisiting all format strings to see if there are no > > > additional > > > characters, otherwise that needs to be addressed first, if feasible. > > > > I was thinking of making such a correction: > > > > - ret = kstrtoull(attr->set_buf, 0, &val); > > + if (attr->set_buf[0] == '-') > > + ret = kstrtoll(attr->set_buf, 0, &val); > > + else > > + ret = kstrtoull(attr->set_buf, 0, &val); > > > > and when I tested the change it worked, but then I noticed this commit: > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/fs/libfs.c?h=v6.0-rc5&id=488dac0c9237647e9b8f788b6a342595bfa40bda > > > > According to this, it previously used simple_strtoll() which supports > > negative values, but was changed to use kstrtoull() to deliberately > > return '-EINVAL' if it gets a negative value. > > > > So I’m not sure debugfs maintainers will be okay with a fix that > > basically reverts the commit I mentioned. > > Hence, what do you suggest to do with my commit? > > Is it ok to leave it as it is today? > > Meanwhile asking is not a problem, at least we will know for sure. > And yes, leave it as is, but point to the thread where you asking > the clarification. For the record: $ git grep -n -A1 -w DEFINE_DEBUGFS_ATTRIBUTE | grep ');' | sed 's,.*\(".*%.*"\).*,\1,' | sort | uniq -c 1 "%08llx\n" 5 "0x%016llx\n" 5 "0x%02llx\n" 5 "0x%04llx\n" 13 "0x%08llx\n" 1 "0x%4.4llx\n" 3 "0x%.4llx\n" 4 "0x%llx\n" 1 "%1lld\n" 40 "%lld\n" 2 "%lli\n" 129 "%llu\n" 1 "%#llx\n" 2 "%llx\n" means that sscanf() should work and fix the issue. You may even propose a patch as a starter for a discussion.
On Wed, Sep 14, 2022 at 05:03:09PM +0300, Andy Shevchenko wrote: > On Wed, Sep 14, 2022 at 12:32:47PM +0300, Andy Shevchenko wrote: > > On Wed, Sep 14, 2022 at 07:26:36AM +0300, Farber, Eliav wrote: > > > On 9/13/2022 8:01 PM, Andy Shevchenko wrote: > > > > On Tue, Sep 13, 2022 at 05:40:16PM +0300, Farber, Eliav wrote: > > > > > On 9/13/2022 4:06 PM, Farber, Eliav wrote: ... > > > > > It seems like debugfs_attr_write() calls simple_attr_write() and it uses > > > > > kstrtoull(), which is why it fails when setting a negative value. > > > > > This is the same also in v6.0-rc5. > > > > > > > > > > debugfs_attr_read() on the other hand does show the correct value also > > > > > when j is negative. > > > > > > > > Which puzzles me since there is a few drivers that use %lld. > > > > Yeah, changing it to > > > > > > > > ret = sscanf(attr->set_buf, attr->fmt, &val); > > > > if (ret != 1) > > > > ret = -EINVAL; > > > > > > > > probably can fix that. Dunno if debugfs maintainer is okay with this. > > > > > > > > P.S. This needs revisiting all format strings to see if there are no > > > > additional > > > > characters, otherwise that needs to be addressed first, if feasible. > > > > > > I was thinking of making such a correction: > > > > > > - ret = kstrtoull(attr->set_buf, 0, &val); > > > + if (attr->set_buf[0] == '-') > > > + ret = kstrtoll(attr->set_buf, 0, &val); > > > + else > > > + ret = kstrtoull(attr->set_buf, 0, &val); > > > > > > and when I tested the change it worked, but then I noticed this commit: > > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/fs/libfs.c?h=v6.0-rc5&id=488dac0c9237647e9b8f788b6a342595bfa40bda > > > > > > According to this, it previously used simple_strtoll() which supports > > > negative values, but was changed to use kstrtoull() to deliberately > > > return '-EINVAL' if it gets a negative value. > > > > > > So I’m not sure debugfs maintainers will be okay with a fix that > > > basically reverts the commit I mentioned. > > > Hence, what do you suggest to do with my commit? > > > Is it ok to leave it as it is today? > > > > Meanwhile asking is not a problem, at least we will know for sure. > > And yes, leave it as is, but point to the thread where you asking > > the clarification. > > For the record: > > $ git grep -n -A1 -w DEFINE_DEBUGFS_ATTRIBUTE | grep ');' | sed 's,.*\(".*%.*"\).*,\1,' | sort | uniq -c > 1 "%08llx\n" > 5 "0x%016llx\n" > 5 "0x%02llx\n" > 5 "0x%04llx\n" > 13 "0x%08llx\n" > 1 "0x%4.4llx\n" > 3 "0x%.4llx\n" > 4 "0x%llx\n" > 1 "%1lld\n" > 40 "%lld\n" > 2 "%lli\n" > 129 "%llu\n" > 1 "%#llx\n" > 2 "%llx\n" > > means that sscanf() should work and fix the issue. You may even propose a patch > as a starter for a discussion. Reading the commit 488dac0c9237 ("libfs: fix error cast of negative value in simple_attr_write()") I think it should be either reverted or fixed, because u64 is not an issue for negative numbers. The %lld and %llu in any case are for 64-bit value, representing it as unsigned simplifies the generic code, but it doesn't mean we can't keep there signed value if we know that (by supplying proper format string). We have 43 current users of signed integer and I'm in doubt this patch doesn't break none of them.
diff --git a/drivers/hwmon/mr75203.c b/drivers/hwmon/mr75203.c index 07668545c3ae..e6b49f810307 100644 --- a/drivers/hwmon/mr75203.c +++ b/drivers/hwmon/mr75203.c @@ -9,6 +9,7 @@ */ #include <linux/bits.h> #include <linux/clk.h> +#include <linux/debugfs.h> #include <linux/hwmon.h> #include <linux/module.h> #include <linux/mod_devicetable.h> @@ -170,6 +171,7 @@ struct pvt_device { struct regmap *v_map; struct clk *clk; struct reset_control *rst; + struct dentry *dbgfs_dir; struct voltage_device *vd; struct voltage_channels vm_channels; struct temp_coeff ts_coeff; @@ -179,6 +181,64 @@ struct pvt_device { u32 ip_freq; }; +static ssize_t pvt_ts_coeff_j_read(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct pvt_device *pvt = file->private_data; + unsigned int len; + char buf[13]; + + len = scnprintf(buf, sizeof(buf), "%d\n", pvt->ts_coeff.j); + + return simple_read_from_buffer(user_buf, count, ppos, buf, len); +} + +static ssize_t pvt_ts_coeff_j_write(struct file *file, + const char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct pvt_device *pvt = file->private_data; + int ret; + + ret = kstrtos32_from_user(user_buf, count, 0, &pvt->ts_coeff.j); + if (ret) + return ret; + + return count; +} + +static const struct file_operations pvt_ts_coeff_j_fops = { + .read = pvt_ts_coeff_j_read, + .write = pvt_ts_coeff_j_write, + .open = simple_open, + .owner = THIS_MODULE, + .llseek = default_llseek, +}; + +static void devm_pvt_ts_dbgfs_remove(void *data) +{ + struct pvt_device *pvt = (struct pvt_device *)data; + + debugfs_remove_recursive(pvt->dbgfs_dir); + pvt->dbgfs_dir = NULL; +} + +static int pvt_ts_dbgfs_create(struct pvt_device *pvt, struct device *dev) +{ + pvt->dbgfs_dir = debugfs_create_dir(dev_name(dev), NULL); + + debugfs_create_u32("ts_coeff_h", 0644, pvt->dbgfs_dir, + &pvt->ts_coeff.h); + debugfs_create_u32("ts_coeff_g", 0644, pvt->dbgfs_dir, + &pvt->ts_coeff.g); + debugfs_create_u32("ts_coeff_cal5", 0644, pvt->dbgfs_dir, + &pvt->ts_coeff.cal5); + debugfs_create_file("ts_coeff_j", 0644, pvt->dbgfs_dir, pvt, + &pvt_ts_coeff_j_fops); + + return devm_add_action_or_reset(dev, devm_pvt_ts_dbgfs_remove, pvt); +} + static umode_t pvt_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel) { @@ -813,6 +873,8 @@ static int mr75203_probe(struct platform_device *pdev) memset32(temp_config, HWMON_T_INPUT, ts_num); pvt_temp.config = temp_config; pvt_info[index++] = &pvt_temp; + + pvt_ts_dbgfs_create(pvt, dev); } if (pd_num) {
This change adds debugfs to read and write temperature sensor coefficients - g, h, j and cal5. The coefficients can vary between product and product, so it can be very useful to be able to modify them on the fly during the calibration process. e.g.: cat /sys/kernel/debug/940f23d0000.pvt/ts_coeff_cal5 4096 echo 83000 > sys/kernel/debug/940f23d0000.pvt/ts_coeff_g Signed-off-by: Eliav Farber <farbere@amazon.com> --- V5 -> V4: - Return j coefficient to use debugfs_create_file() instead of debugfs_create_u32() because j is signed. V4 -> V3: - Remove check of the debugfs_create_dir() return value. - Use debugfs_create_u32() instead of debugfs_create_file(). - Return devm_add_action_or_reset() without checking return value and printing an error message on failure. drivers/hwmon/mr75203.c | 62 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+)