From: Bolarinwa Olayemi Saheed <[email protected]>
On failure, pcie_capabiility_read_*() will set the status value,
its last parameter to 0 and not ~0.
This bug fix checks for the proper value.
Bolarinwa Olayemi Saheed (2):
PCI/PME: Fix wrong failure check on pcie_capability_read_*()
PCI: pciehp: Fix wrong failure check on pcie_capability_read_*()
drivers/pci/hotplug/pciehp_hpc.c | 10 +++++-----
drivers/pci/pcie/pme.c | 4 ++--
2 files changed, 7 insertions(+), 7 deletions(-)
--
2.18.2
From: Bolarinwa Olayemi Saheed <[email protected]>
On failure, pcie_capabiility_read_*() will set rtsta to 0 and not ~0.
This bug fix checks for the proper value.
Signed-off-by: Bolarinwa Olayemi Saheed <[email protected]>
---
drivers/pci/pcie/pme.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/pcie/pme.c b/drivers/pci/pcie/pme.c
index 6a32970bb731..1d1d06f06335 100644
--- a/drivers/pci/pcie/pme.c
+++ b/drivers/pci/pcie/pme.c
@@ -224,7 +224,7 @@ static void pcie_pme_work_fn(struct work_struct *work)
break;
pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta);
- if (rtsta == (u32) ~0)
+ if (rtsta == (u32)0)
break;
if (rtsta & PCI_EXP_RTSTA_PME) {
@@ -274,7 +274,7 @@ static irqreturn_t pcie_pme_irq(int irq, void *context)
spin_lock_irqsave(&data->lock, flags);
pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta);
- if (rtsta == (u32) ~0 || !(rtsta & PCI_EXP_RTSTA_PME)) {
+ if (rtsta == (u32)0 || !(rtsta & PCI_EXP_RTSTA_PME)) {
spin_unlock_irqrestore(&data->lock, flags);
return IRQ_NONE;
}
--
2.18.2
From: Bolarinwa Olayemi Saheed <[email protected]>
On failure, pcie_capabiility_read_*() will set the status value,
its last parameter to 0 and not ~0.
This bug fix checks for the proper value.
Signed-off-by: Bolarinwa Olayemi Saheed <[email protected]>
---
drivers/pci/hotplug/pciehp_hpc.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 53433b37e181..c1a67054948a 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -89,7 +89,7 @@ static int pcie_poll_cmd(struct controller *ctrl, int timeout)
do {
pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
- if (slot_status == (u16) ~0) {
+ if (slot_status == (u16)0) {
ctrl_info(ctrl, "%s: no response from device\n",
__func__);
return 0;
@@ -165,7 +165,7 @@ static void pcie_do_write_cmd(struct controller *ctrl, u16 cmd,
pcie_wait_cmd(ctrl);
pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
- if (slot_ctrl == (u16) ~0) {
+ if (slot_ctrl == (u16)0) {
ctrl_info(ctrl, "%s: no response from device\n", __func__);
goto out;
}
@@ -236,7 +236,7 @@ int pciehp_check_link_active(struct controller *ctrl)
int ret;
ret = pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
- if (ret == PCIBIOS_DEVICE_NOT_FOUND || lnk_status == (u16)~0)
+ if (ret == PCIBIOS_DEVICE_NOT_FOUND || lnk_status == (u16)0)
return -ENODEV;
ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
@@ -440,7 +440,7 @@ int pciehp_card_present(struct controller *ctrl)
int ret;
ret = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
- if (ret == PCIBIOS_DEVICE_NOT_FOUND || slot_status == (u16)~0)
+ if (ret == PCIBIOS_DEVICE_NOT_FOUND || slot_status == (u16)0)
return -ENODEV;
return !!(slot_status & PCI_EXP_SLTSTA_PDS);
@@ -592,7 +592,7 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id)
read_status:
pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &status);
- if (status == (u16) ~0) {
+ if (status == (u16)0) {
ctrl_info(ctrl, "%s: no response from device\n", __func__);
if (parent)
pm_runtime_put(parent);
--
2.18.2
On Fri, Jun 19, 2020 at 10:12:19PM +0200, [email protected] wrote:
> On failure, pcie_capabiility_read_*() will set the status value,
> its last parameter to 0 and not ~0.
> This bug fix checks for the proper value.
If a config space read times out, the PCIe controller fabricates
an "all ones" response. The code is checking for such a timeout,
not for an error. Hence the code is fine.
Thanks,
Lukas
>
> Signed-off-by: Bolarinwa Olayemi Saheed <[email protected]>
> ---
> drivers/pci/hotplug/pciehp_hpc.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
> index 53433b37e181..c1a67054948a 100644
> --- a/drivers/pci/hotplug/pciehp_hpc.c
> +++ b/drivers/pci/hotplug/pciehp_hpc.c
> @@ -89,7 +89,7 @@ static int pcie_poll_cmd(struct controller *ctrl, int timeout)
>
> do {
> pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
> - if (slot_status == (u16) ~0) {
> + if (slot_status == (u16)0) {
> ctrl_info(ctrl, "%s: no response from device\n",
> __func__);
> return 0;
> @@ -165,7 +165,7 @@ static void pcie_do_write_cmd(struct controller *ctrl, u16 cmd,
> pcie_wait_cmd(ctrl);
>
> pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
> - if (slot_ctrl == (u16) ~0) {
> + if (slot_ctrl == (u16)0) {
> ctrl_info(ctrl, "%s: no response from device\n", __func__);
> goto out;
> }
> @@ -236,7 +236,7 @@ int pciehp_check_link_active(struct controller *ctrl)
> int ret;
>
> ret = pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
> - if (ret == PCIBIOS_DEVICE_NOT_FOUND || lnk_status == (u16)~0)
> + if (ret == PCIBIOS_DEVICE_NOT_FOUND || lnk_status == (u16)0)
> return -ENODEV;
>
> ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
> @@ -440,7 +440,7 @@ int pciehp_card_present(struct controller *ctrl)
> int ret;
>
> ret = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
> - if (ret == PCIBIOS_DEVICE_NOT_FOUND || slot_status == (u16)~0)
> + if (ret == PCIBIOS_DEVICE_NOT_FOUND || slot_status == (u16)0)
> return -ENODEV;
>
> return !!(slot_status & PCI_EXP_SLTSTA_PDS);
> @@ -592,7 +592,7 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id)
>
> read_status:
> pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &status);
> - if (status == (u16) ~0) {
> + if (status == (u16)0) {
> ctrl_info(ctrl, "%s: no response from device\n", __func__);
> if (parent)
> pm_runtime_put(parent);
> --
> 2.18.2
On Sat, Jun 20, 2020 at 11:09:36AM +0200, Lukas Wunner wrote:
> On Fri, Jun 19, 2020 at 10:12:19PM +0200, [email protected] wrote:
> > On failure, pcie_capabiility_read_*() will set the status value,
> > its last parameter to 0 and not ~0.
> > This bug fix checks for the proper value.
>
> If a config space read times out, the PCIe controller fabricates
> an "all ones" response. The code is checking for such a timeout,
> not for an error. Hence the code is fine.
In the typical case, the pci_read_config_word() done by
pcie_capability_read_word() will not return an error, so if the read
times out, we should see slot_status == ~0.
But if it's possible to set dev->error_state ==
pci_channel_io_perm_failure, pci_read_config_word() will return an
error because pci_dev_is_disconnected(), so slot_status would be 0.
There are a dozen or so places that set dev->error_state. It doesn't
look *likely* that any of them would cause this, but it doesn't
instill confidence.
It would be a lot nicer if we didn't have to worry about both the 0
and ~0 cases. I keep coming back to the idea of removing the "*val
= 0" code from pcie_capability_read_word() so we wouldn't have that
special case.
In any case, this particular patch doesn't seem like quite the right
fix, so I'll drop it.
> > Signed-off-by: Bolarinwa Olayemi Saheed <[email protected]>
> > ---
> > drivers/pci/hotplug/pciehp_hpc.c | 10 +++++-----
> > 1 file changed, 5 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
> > index 53433b37e181..c1a67054948a 100644
> > --- a/drivers/pci/hotplug/pciehp_hpc.c
> > +++ b/drivers/pci/hotplug/pciehp_hpc.c
> > @@ -89,7 +89,7 @@ static int pcie_poll_cmd(struct controller *ctrl, int timeout)
> >
> > do {
> > pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
> > - if (slot_status == (u16) ~0) {
> > + if (slot_status == (u16)0) {
> > ctrl_info(ctrl, "%s: no response from device\n",
> > __func__);
> > return 0;
> > @@ -165,7 +165,7 @@ static void pcie_do_write_cmd(struct controller *ctrl, u16 cmd,
> > pcie_wait_cmd(ctrl);
> >
> > pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
> > - if (slot_ctrl == (u16) ~0) {
> > + if (slot_ctrl == (u16)0) {
> > ctrl_info(ctrl, "%s: no response from device\n", __func__);
> > goto out;
> > }
> > @@ -236,7 +236,7 @@ int pciehp_check_link_active(struct controller *ctrl)
> > int ret;
> >
> > ret = pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
> > - if (ret == PCIBIOS_DEVICE_NOT_FOUND || lnk_status == (u16)~0)
> > + if (ret == PCIBIOS_DEVICE_NOT_FOUND || lnk_status == (u16)0)
> > return -ENODEV;
> >
> > ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
> > @@ -440,7 +440,7 @@ int pciehp_card_present(struct controller *ctrl)
> > int ret;
> >
> > ret = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
> > - if (ret == PCIBIOS_DEVICE_NOT_FOUND || slot_status == (u16)~0)
> > + if (ret == PCIBIOS_DEVICE_NOT_FOUND || slot_status == (u16)0)
> > return -ENODEV;
> >
> > return !!(slot_status & PCI_EXP_SLTSTA_PDS);
> > @@ -592,7 +592,7 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id)
> >
> > read_status:
> > pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &status);
> > - if (status == (u16) ~0) {
> > + if (status == (u16)0) {
> > ctrl_info(ctrl, "%s: no response from device\n", __func__);
> > if (parent)
> > pm_runtime_put(parent);
> > --
> > 2.18.2