| Message ID | 20240903184710.1552067-1-nm@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [V2] mfd: syscon: Use regmap max_register_is_0 as needed | expand |
On 13:47-20240903, Nishanth Menon wrote: > syscon has always set the optional max_register configuration of > regmap to ensure the correct checks are in place. However, a recent > commit 0ec74ad3c157 ("regmap: rework ->max_register handling") > introduced explicit configuration in regmap framework for register > maps that is exactly 1 register, when max_register is pointing to a > valid register 0. This commit solved a previous limitation of regmap > framework. > > Update syscon driver to consistent in regmap configuration for > all sizes of syscons by using this new capability by setting > max_register_is_0, when the max_register is valid and 0. > > Signed-off-by: Nishanth Menon <nm@ti.com> > --- > > Based on my search > https://gist.github.com/nmenon/d537096d041fa553565fba7577d2cd24, the > pattern of syscon registers that may potentially be impacted by this > patch (that are exactly 1 register wide) is probably limited, though > this patch in itself was inspired by a buggy driver code fixed in > https://lore.kernel.org/linux-pm/20240828131915.3198081-1-nm@ti.com/ > I have tried to Cc lists that may be interested in looking closer to > avoid un-intended side-effects. > > Changes since V1: > * Incorporate review comments by rewording commit message and $subject > and dropped Fixes. > * No functional change to the patch. > * Expand the CC list to notify potential users. > > V1: https://lore.kernel.org/all/20240828121008.3066002-1-nm@ti.com/ > > Cc: Mark Brown <broonie@kernel.org> > Cc: Shawn Guo <shawnguo@kernel.org> > Cc: linux-arm-msm@vger.kernel.org > Cc: Bjorn Andersson <andersson@kernel.org> > Cc: bcm-kernel-feedback-list@broadcom.com > Cc: Florian Fainelli <florian.fainelli@broadcom.com> > Cc: linux-stm32@st-md-mailman.stormreply.com > Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> A gentle ping. > > drivers/mfd/syscon.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c > index 2ce15f60eb10..3e1d699ba934 100644 > --- a/drivers/mfd/syscon.c > +++ b/drivers/mfd/syscon.c > @@ -108,6 +108,8 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_res) > syscon_config.reg_stride = reg_io_width; > syscon_config.val_bits = reg_io_width * 8; > syscon_config.max_register = resource_size(&res) - reg_io_width; > + if (!syscon_config.max_register) > + syscon_config.max_register_is_0 = true; > > regmap = regmap_init_mmio(NULL, base, &syscon_config); > kfree(syscon_config.name); > @@ -357,6 +359,9 @@ static int syscon_probe(struct platform_device *pdev) > return -ENOMEM; > > syscon_config.max_register = resource_size(res) - 4; > + if (!syscon_config.max_register) > + syscon_config.max_register_is_0 = true; > + > if (pdata) > syscon_config.name = pdata->label; > syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config); > > -- > 2.46.0 > >
On Tue, 03 Sep 2024 13:47:10 -0500, Nishanth Menon wrote: > syscon has always set the optional max_register configuration of > regmap to ensure the correct checks are in place. However, a recent > commit 0ec74ad3c157 ("regmap: rework ->max_register handling") > introduced explicit configuration in regmap framework for register > maps that is exactly 1 register, when max_register is pointing to a > valid register 0. This commit solved a previous limitation of regmap > framework. > > [...] Applied, thanks! [1/1] mfd: syscon: Use regmap max_register_is_0 as needed commit: bf5b2ddf06da57fa623c11d599697a98f1007752 -- Lee Jones [李琼斯]
diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c index 2ce15f60eb10..3e1d699ba934 100644 --- a/drivers/mfd/syscon.c +++ b/drivers/mfd/syscon.c @@ -108,6 +108,8 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_res) syscon_config.reg_stride = reg_io_width; syscon_config.val_bits = reg_io_width * 8; syscon_config.max_register = resource_size(&res) - reg_io_width; + if (!syscon_config.max_register) + syscon_config.max_register_is_0 = true; regmap = regmap_init_mmio(NULL, base, &syscon_config); kfree(syscon_config.name); @@ -357,6 +359,9 @@ static int syscon_probe(struct platform_device *pdev) return -ENOMEM; syscon_config.max_register = resource_size(res) - 4; + if (!syscon_config.max_register) + syscon_config.max_register_is_0 = true; + if (pdata) syscon_config.name = pdata->label; syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
syscon has always set the optional max_register configuration of regmap to ensure the correct checks are in place. However, a recent commit 0ec74ad3c157 ("regmap: rework ->max_register handling") introduced explicit configuration in regmap framework for register maps that is exactly 1 register, when max_register is pointing to a valid register 0. This commit solved a previous limitation of regmap framework. Update syscon driver to consistent in regmap configuration for all sizes of syscons by using this new capability by setting max_register_is_0, when the max_register is valid and 0. Signed-off-by: Nishanth Menon <nm@ti.com> --- Based on my search https://gist.github.com/nmenon/d537096d041fa553565fba7577d2cd24, the pattern of syscon registers that may potentially be impacted by this patch (that are exactly 1 register wide) is probably limited, though this patch in itself was inspired by a buggy driver code fixed in https://lore.kernel.org/linux-pm/20240828131915.3198081-1-nm@ti.com/ I have tried to Cc lists that may be interested in looking closer to avoid un-intended side-effects. Changes since V1: * Incorporate review comments by rewording commit message and $subject and dropped Fixes. * No functional change to the patch. * Expand the CC list to notify potential users. V1: https://lore.kernel.org/all/20240828121008.3066002-1-nm@ti.com/ Cc: Mark Brown <broonie@kernel.org> Cc: Shawn Guo <shawnguo@kernel.org> Cc: linux-arm-msm@vger.kernel.org Cc: Bjorn Andersson <andersson@kernel.org> Cc: bcm-kernel-feedback-list@broadcom.com Cc: Florian Fainelli <florian.fainelli@broadcom.com> Cc: linux-stm32@st-md-mailman.stormreply.com Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> drivers/mfd/syscon.c | 5 +++++ 1 file changed, 5 insertions(+)