Re: [PATCH] Revert "PCI: j721e: Drop redundant struct device *"

From: Rob Herring
Date: Mon Jan 24 2022 - 10:24:37 EST


On Mon, Jan 24, 2022 at 6:21 AM Christian Gmeiner
<christian.gmeiner@xxxxxxxxx> wrote:
>
> This reverts commit 19e863828acf6d8ac8475ba1fd93c0fe17fdc4ef.
>
> Fixes the following oops:

Perhaps explain why the 2nd struct device was not redundant. Is this
not just a case of the dev pointer not getting set early enough?

> Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
> Internal error: Oops: 96000004 [#1] PREEMPT SMP
> Modules linked in:
> CPU: 1 PID: 7 Comm: kworker/u4:0 Not tainted 5.17.0-rc1-00086-ge38b27816fea-dirty #71
> Hardware name: CPE0108 (DT)
> Workqueue: events_unbound deferred_probe_work_func
> pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : j721e_pcie_probe+0x184/0x600
> lr : j721e_pcie_probe+0x170/0x600
> sp : ffff80000957bae0
> x29: ffff80000957bae0 x28: ffff800009357000 x27: ffff00000000c078
> x26: ffff00003fe047a8 x25: 0000000000000000 x24: ffff0000000f5280
> x23: ffff800008c98f78 x22: ffff800008f90ff0 x21: ffff000000231410
> x20: ffff000002ef2780 x19: 0000000000000021 x18: 0000000000000001
> x17: 0000000000000000 x16: 0000000000058c00 x15: ffffffffffffffff
> x14: ffffffffffffffff x13: 0000000000000010 x12: 0101010101010101
> x11: 0000000000000040 x10: ffff8000093e06c8 x9 : ffff8000093e06c0
> x8 : ffff000000400270 x7 : 0000000000000000 x6 : ffff000000231590
> x5 : ffff80000957b9e0 x4 : 0000000000000000 x3 : ffff0000002314f4
> x2 : 0000000000000000 x1 : ffff0000000f5280 x0 : 0000000000000000
> Call trace:
> j721e_pcie_probe+0x184/0x600
> platform_probe+0x68/0xe0
> really_probe+0x144/0x320
> __driver_probe_device+0xc4/0xe0
> driver_probe_device+0x7c/0x110
> __device_attach_driver+0x90/0xe0
> bus_for_each_drv+0x78/0xd0
> __device_attach+0xf0/0x150
> device_initial_probe+0x14/0x20
> bus_probe_device+0x9c/0xb0
> deferred_probe_work_func+0x88/0xc0
> process_one_work+0x1bc/0x340
> worker_thread+0x1f8/0x420
> kthread+0x110/0x120
> ret_from_fork+0x10/0x20
> Code: f9400280 a90573fb d0005396 913fc2d6 (f9400800)
>
> Fixes: 19e863828acf ("PCI: j721e: Drop redundant struct device *")
> Signed-off-by: Christian Gmeiner <christian.gmeiner@xxxxxxxxx>
> ---
> drivers/pci/controller/cadence/pci-j721e.c | 14 ++++++++------
> 1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/pci/controller/cadence/pci-j721e.c b/drivers/pci/controller/cadence/pci-j721e.c
> index 489586a4cdc7..cd43d1898482 100644
> --- a/drivers/pci/controller/cadence/pci-j721e.c
> +++ b/drivers/pci/controller/cadence/pci-j721e.c
> @@ -51,10 +51,11 @@ enum link_status {
> #define MAX_LANES 2
>
> struct j721e_pcie {
> - struct cdns_pcie *cdns_pcie;
> + struct device *dev;
> struct clk *refclk;
> u32 mode;
> u32 num_lanes;
> + struct cdns_pcie *cdns_pcie;
> void __iomem *user_cfg_base;
> void __iomem *intd_cfg_base;
> u32 linkdown_irq_regfield;
> @@ -98,7 +99,7 @@ static inline void j721e_pcie_intd_writel(struct j721e_pcie *pcie, u32 offset,
> static irqreturn_t j721e_pcie_link_irq_handler(int irq, void *priv)
> {
> struct j721e_pcie *pcie = priv;
> - struct device *dev = pcie->cdns_pcie->dev;
> + struct device *dev = pcie->dev;
> u32 reg;
>
> reg = j721e_pcie_intd_readl(pcie, STATUS_REG_SYS_2);
> @@ -164,7 +165,7 @@ static const struct cdns_pcie_ops j721e_pcie_ops = {
> static int j721e_pcie_set_mode(struct j721e_pcie *pcie, struct regmap *syscon,
> unsigned int offset)
> {
> - struct device *dev = pcie->cdns_pcie->dev;
> + struct device *dev = pcie->dev;
> u32 mask = J721E_MODE_RC;
> u32 mode = pcie->mode;
> u32 val = 0;
> @@ -183,7 +184,7 @@ static int j721e_pcie_set_mode(struct j721e_pcie *pcie, struct regmap *syscon,
> static int j721e_pcie_set_link_speed(struct j721e_pcie *pcie,
> struct regmap *syscon, unsigned int offset)
> {
> - struct device *dev = pcie->cdns_pcie->dev;
> + struct device *dev = pcie->dev;
> struct device_node *np = dev->of_node;
> int link_speed;
> u32 val = 0;
> @@ -204,7 +205,7 @@ static int j721e_pcie_set_link_speed(struct j721e_pcie *pcie,
> static int j721e_pcie_set_lane_count(struct j721e_pcie *pcie,
> struct regmap *syscon, unsigned int offset)
> {
> - struct device *dev = pcie->cdns_pcie->dev;
> + struct device *dev = pcie->dev;
> u32 lanes = pcie->num_lanes;
> u32 val = 0;
> int ret;
> @@ -219,7 +220,7 @@ static int j721e_pcie_set_lane_count(struct j721e_pcie *pcie,
>
> static int j721e_pcie_ctrl_init(struct j721e_pcie *pcie)
> {
> - struct device *dev = pcie->cdns_pcie->dev;
> + struct device *dev = pcie->dev;
> struct device_node *node = dev->of_node;
> struct of_phandle_args args;
> unsigned int offset = 0;
> @@ -376,6 +377,7 @@ static int j721e_pcie_probe(struct platform_device *pdev)
> if (!pcie)
> return -ENOMEM;
>
> + pcie->dev = dev;
> pcie->mode = mode;
> pcie->linkdown_irq_regfield = data->linkdown_irq_regfield;
>
> --
> 2.34.1
>