2023-11-27 23:15:39

by claudiu beznea

[permalink] [raw]
Subject: [PATCH 0/6] net: ravb: Fixes for the ravb driver

From: Claudiu Beznea <[email protected]>

Hi,

This series adds some fixes for ravb driver. Patches in this series
were initilly part of series at [1].

Changes since [1]:
- addressed review comments
- added patch 6/6

[1] https://lore.kernel.org/all/[email protected]/

Claudiu Beznea (6):
net: ravb: Check return value of reset_control_deassert()
net: ravb: Use pm_runtime_resume_and_get()
net: ravb: Make write access to CXR35 first before accessing other
EMAC registers
net: ravb: Start TX queues after HW initialization succeeded
net: ravb: Stop DMA in case of failures on ravb_open()
net: ravb: Keep reverse order of operations in ravb_remove()

drivers/net/ethernet/renesas/ravb_main.c | 58 ++++++++++++++----------
1 file changed, 35 insertions(+), 23 deletions(-)

--
2.39.2


2023-11-28 06:57:57

by claudiu beznea

[permalink] [raw]
Subject: [PATCH 6/6] net: ravb: Keep reverse order of operations in ravb_remove()

From: Claudiu Beznea <[email protected]>

On RZ/G3S SMARC Carrier II board having RGMII connections b/w Ethernet
MACs and PHYs it has been discovered that doing unbind/bind for ravb
driver in a loop leads to wrong speed and duplex for Ethernet links and
broken connectivity (the connectivity cannot be restored even with
bringing interface down/up). Before doing unbind/bind the Ethernet
interfaces were configured though systemd. The sh instructions used to
do unbind/bind were:

$ cd /sys/bus/platform/drivers/ravb/
$ while :; do echo 11c30000.ethernet > unbind ; \
echo 11c30000.ethernet > bind; done

It has been discovered that there is a race b/w IOCTLs initialized by
systemd at the response of success binding and the
"ravb_write(ndev, CCC_OPC_RESET, CCC)" instruction in ravb_remove() as
follows:

1/ as a result of bind success the user space open/configures the
interfaces tough an IOCTL; the following stack trace has been
identified on RZ/G3S:

Call trace:
dump_backtrace+0x9c/0x100
show_stack+0x20/0x38
dump_stack_lvl+0x48/0x60
dump_stack+0x18/0x28
ravb_open+0x70/0xa58
__dev_open+0xf4/0x1e8
__dev_change_flags+0x198/0x218
dev_change_flags+0x2c/0x80
devinet_ioctl+0x640/0x708
inet_ioctl+0x1e4/0x200
sock_do_ioctl+0x50/0x108
sock_ioctl+0x240/0x358
__arm64_sys_ioctl+0xb0/0x100
invoke_syscall+0x50/0x128
el0_svc_common.constprop.0+0xc8/0xf0
do_el0_svc+0x24/0x38
el0_svc+0x34/0xb8
el0t_64_sync_handler+0xc0/0xc8
el0t_64_sync+0x190/0x198

2/ this call may execute concurrently with ravb_remove() as the
unbind/bind operation was executed in a loop
3/ if the operation mode is changed to RESET (though
ravb_write(ndev, CCC_OPC_RESET, CCC) instruction in ravb_remove())
while the above ravb_open() is in progress it may lead to MAC
(or PHY, or MAC-PHY connection, the right point hasn't been identified
at the moment) to be broken, thus the Ethernet connectivity fails to
restore.

The simple fix for this is to move ravb_write(ndev, CCC_OPC_RESET, CCC))
after unregister_netdev() to avoid resetting the controller while the
netdev interface is still registered.

To avoid future issues in ravb_remove(), the patch follows the proper order
of operations in ravb_remove(): reverse order compared with ravb_probe().
This avoids described races as the IOCTLs as well as unregister_netdev()
(called now at the beginning of ravb_remove()) calls rtnl_lock() before
continuing and IOCTLs check (though devinet_ioctl()) if device is still
registered just after taking the lock:

int devinet_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr)
{
// ...

rtnl_lock();

ret = -ENODEV;
dev = __dev_get_by_name(net, ifr->ifr_name);
if (!dev)
goto done;

// ...
done:
rtnl_unlock();
out:
return ret;
}

Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
Signed-off-by: Claudiu Beznea <[email protected]>
---

Changes since [1]:
- none; this patch is new

[1] https://lore.kernel.org/all/[email protected]/

drivers/net/ethernet/renesas/ravb_main.c | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 805720166ef3..9cad10db59b7 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -2894,22 +2894,26 @@ static void ravb_remove(struct platform_device *pdev)
struct ravb_private *priv = netdev_priv(ndev);
const struct ravb_hw_info *info = priv->info;

- /* Stop PTP Clock driver */
- if (info->ccc_gac)
- ravb_ptp_stop(ndev);
-
- clk_disable_unprepare(priv->gptp_clk);
- clk_disable_unprepare(priv->refclk);
-
- /* Set reset mode */
- ravb_write(ndev, CCC_OPC_RESET, CCC);
unregister_netdev(ndev);
if (info->nc_queues)
netif_napi_del(&priv->napi[RAVB_NC]);
netif_napi_del(&priv->napi[RAVB_BE]);
+
ravb_mdio_release(priv);
+
+ /* Stop PTP Clock driver */
+ if (info->ccc_gac)
+ ravb_ptp_stop(ndev);
+
dma_free_coherent(ndev->dev.parent, priv->desc_bat_size, priv->desc_bat,
priv->desc_bat_dma);
+
+ /* Set reset mode */
+ ravb_write(ndev, CCC_OPC_RESET, CCC);
+
+ clk_disable_unprepare(priv->gptp_clk);
+ clk_disable_unprepare(priv->refclk);
+
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
reset_control_assert(priv->rstc);
--
2.39.2

2023-11-28 07:01:00

by claudiu beznea

[permalink] [raw]
Subject: [PATCH 4/6] net: ravb: Start TX queues after HW initialization succeeded

From: Claudiu Beznea <[email protected]>

ravb_phy_start() may fail. If that happens, the TX queues will remain
started. Thus, move the netif_tx_start_all_queues() after PHY is
successfully initialized.

Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
Signed-off-by: Claudiu Beznea <[email protected]>
Reviewed-by: Sergey Shtylyov <[email protected]>
---

Changes since [1]:
- collected Rb tag

[1] https://lore.kernel.org/all/[email protected]/

drivers/net/ethernet/renesas/ravb_main.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 2d4f4fb3d16e..f7e62e6c9df9 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1812,13 +1812,13 @@ static int ravb_open(struct net_device *ndev)
if (info->gptp)
ravb_ptp_init(ndev, priv->pdev);

- netif_tx_start_all_queues(ndev);
-
/* PHY control start */
error = ravb_phy_start(ndev);
if (error)
goto out_ptp_stop;

+ netif_tx_start_all_queues(ndev);
+
return 0;

out_ptp_stop:
--
2.39.2

2023-11-28 13:00:16

by claudiu beznea

[permalink] [raw]
Subject: [PATCH 5/6] net: ravb: Stop DMA in case of failures on ravb_open()

From: Claudiu Beznea <[email protected]>

In case ravb_phy_start() returns with error the settings applied in
ravb_dmac_init() are not reverted (e.g. config mode). For this call
ravb_stop_dma() on failure path of ravb_open().

Fixes: a0d2f20650e8 ("Renesas Ethernet AVB PTP clock driver")
Signed-off-by: Claudiu Beznea <[email protected]>
Reviewed-by: Sergey Shtylyov <[email protected]>
---

Changes since [1]:
- s/ravb_dma_init/ravb_dmac_init in commit description
- collected Rb tag

[1] https://lore.kernel.org/all/[email protected]/

drivers/net/ethernet/renesas/ravb_main.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index f7e62e6c9df9..805720166ef3 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1825,6 +1825,7 @@ static int ravb_open(struct net_device *ndev)
/* Stop PTP Clock driver */
if (info->gptp)
ravb_ptp_stop(ndev);
+ ravb_stop_dma(ndev);
out_free_irq_mgmta:
if (!info->multi_irqs)
goto out_free_irq;
--
2.39.2

2023-11-29 06:30:46

by claudiu beznea

[permalink] [raw]
Subject: [PATCH 2/6] net: ravb: Use pm_runtime_resume_and_get()

From: Claudiu Beznea <[email protected]>

pm_runtime_get_sync() may return an error. In case it returns with an error
dev->power.usage_count needs to be decremented. pm_runtime_resume_and_get()
takes care of this. Thus use it.

Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
Signed-off-by: Claudiu Beznea <[email protected]>
---

Changes since [1]:
- added goto label for pm_runtime_disable(); with this innecessary
changes were removed

[1] https://lore.kernel.org/all/[email protected]/

drivers/net/ethernet/renesas/ravb_main.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 50c4c79be035..cd3474168452 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -2650,7 +2650,9 @@ static int ravb_probe(struct platform_device *pdev)
goto out_free_netdev;

pm_runtime_enable(&pdev->dev);
- pm_runtime_get_sync(&pdev->dev);
+ error = pm_runtime_resume_and_get(&pdev->dev);
+ if (error < 0)
+ goto out_runtime_disable;

if (info->multi_irqs) {
if (info->err_mgmt_irqs)
@@ -2876,6 +2878,7 @@ static int ravb_probe(struct platform_device *pdev)
clk_disable_unprepare(priv->refclk);
out_release:
pm_runtime_put(&pdev->dev);
+out_runtime_disable:
pm_runtime_disable(&pdev->dev);
reset_control_assert(rstc);
out_free_netdev:
--
2.39.2

2023-11-29 06:35:46

by claudiu beznea

[permalink] [raw]
Subject: [PATCH 3/6] net: ravb: Make write access to CXR35 first before accessing other EMAC registers

From: Claudiu Beznea <[email protected]>

Hardware manual of RZ/G3S (and RZ/G2L) specifies the following on the
description of CXR35 register (chapter "PHY interface select register
(CXR35)"): "After release reset, make write-access to this register before
making write-access to other registers (except MDIOMOD). Even if not need
to change the value of this register, make write-access to this register
at least one time. Because RGMII/MII MODE is recognized by accessing this
register".

The setup procedure for EMAC module (chapter "Setup procedure" of RZ/G3S,
RZ/G2L manuals) specifies the E-MAC.CXR35 register is the first EMAC
register that is to be configured.

Note [A] from chapter "PHY interface select register (CXR35)" specifies
the following:
[A] The case which CXR35 SEL_XMII is used for the selection of RGMII/MII
in APB Clock 100 MHz.
(1) To use RGMII interface, Set ‘H’03E8_0000’ to this register.
(2) To use MII interface, Set ‘H’03E8_0002’ to this register.

Take into account these indication.

Fixes: 1089877ada8d ("ravb: Add RZ/G2L MII interface support")
Signed-off-by: Claudiu Beznea <[email protected]>
Reviewed-by: Sergey Shtylyov <[email protected]>
---

Changes since [1]:
- collected Rb tag

[1] https://lore.kernel.org/all/[email protected]/

drivers/net/ethernet/renesas/ravb_main.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index cd3474168452..2d4f4fb3d16e 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -515,6 +515,15 @@ static void ravb_emac_init_gbeth(struct net_device *ndev)
{
struct ravb_private *priv = netdev_priv(ndev);

+ if (priv->phy_interface == PHY_INTERFACE_MODE_MII) {
+ ravb_write(ndev, (1000 << 16) | CXR35_SEL_XMII_MII, CXR35);
+ ravb_modify(ndev, CXR31, CXR31_SEL_LINK0 | CXR31_SEL_LINK1, 0);
+ } else {
+ ravb_write(ndev, (1000 << 16) | CXR35_SEL_XMII_RGMII, CXR35);
+ ravb_modify(ndev, CXR31, CXR31_SEL_LINK0 | CXR31_SEL_LINK1,
+ CXR31_SEL_LINK0);
+ }
+
/* Receive frame limit set register */
ravb_write(ndev, GBETH_RX_BUFF_MAX + ETH_FCS_LEN, RFLR);

@@ -537,14 +546,6 @@ static void ravb_emac_init_gbeth(struct net_device *ndev)

/* E-MAC interrupt enable register */
ravb_write(ndev, ECSIPR_ICDIP, ECSIPR);
-
- if (priv->phy_interface == PHY_INTERFACE_MODE_MII) {
- ravb_modify(ndev, CXR31, CXR31_SEL_LINK0 | CXR31_SEL_LINK1, 0);
- ravb_write(ndev, (1000 << 16) | CXR35_SEL_XMII_MII, CXR35);
- } else {
- ravb_modify(ndev, CXR31, CXR31_SEL_LINK0 | CXR31_SEL_LINK1,
- CXR31_SEL_LINK0);
- }
}

static void ravb_emac_init_rcar(struct net_device *ndev)
--
2.39.2

2023-11-30 07:12:50

by claudiu beznea

[permalink] [raw]
Subject: [PATCH 1/6] net: ravb: Check return value of reset_control_deassert()

From: Claudiu Beznea <[email protected]>

reset_control_deassert() could return an error. Some devices cannot work
if reset signal de-assert operation fails. To avoid this check the return
code of reset_control_deassert() in ravb_probe() and take proper action.

Fixes: 0d13a1a464a0 ("ravb: Add reset support")
Signed-off-by: Claudiu Beznea <[email protected]>
---

Changes since [1]:
- added goto label for free_netdev()

[1] https://lore.kernel.org/all/[email protected]/

drivers/net/ethernet/renesas/ravb_main.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index c70cff80cc99..50c4c79be035 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -2645,7 +2645,10 @@ static int ravb_probe(struct platform_device *pdev)
ndev->features = info->net_features;
ndev->hw_features = info->net_hw_features;

- reset_control_deassert(rstc);
+ error = reset_control_deassert(rstc);
+ if (error)
+ goto out_free_netdev;
+
pm_runtime_enable(&pdev->dev);
pm_runtime_get_sync(&pdev->dev);

@@ -2872,11 +2875,11 @@ static int ravb_probe(struct platform_device *pdev)
out_disable_refclk:
clk_disable_unprepare(priv->refclk);
out_release:
- free_netdev(ndev);
-
pm_runtime_put(&pdev->dev);
pm_runtime_disable(&pdev->dev);
reset_control_assert(rstc);
+out_free_netdev:
+ free_netdev(ndev);
return error;
}

--
2.39.2