[PATCH net-next v4 1/8] octeon_ep: defer probe if firmware not ready

Veerasenareddy Burru
2023-03-22T09:20:23Z

Defer probe if firmware is not ready for device usage.

Signed-off-by: Veerasenareddy Burru <vburru@marvell.com>
Signed-off-by: Abhijit Ayarekar <aayarekar@marvell.com>
Signed-off-by: Satananda Burla <sburla@marvell.com>
---
v3 -> v4:
* address review comments
https://lore.kernel.org/all/Y+vFlfakHj33DEkt@boxer/
- fix return statement for get_fw_ready_status().

v2 -> v3:
* fix review comments
https://lore.kernel.org/all/Y4chWyR6qTlptkTE@unreal/
- change get_fw_ready_status() to return bool
- fix the success oriented flow while looking for
PCI extended capability

v1 -> v2:
* was scheduling workqueue task to wait for firmware ready,
to probe/initialize the device.
* now, removed the workqueue task; the probe returns EPROBE_DEFER,
if firmware is not ready.
* removed device status oct->status, as it is not required with the
modified implementation.

.../ethernet/marvell/octeon_ep/octep_main.c | 26 +++++++++++++++++++
1 file changed, 26 insertions(+)

diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
index fdce78ceea87..0a50da52dc27 100644
--- a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
+++ b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
@@ -1016,6 +1016,26 @@ static void octep_device_cleanup(struct octep_device *oct)
oct->conf = NULL;
}

+static bool get_fw_ready_status(struct pci_dev *pdev)
+{
+ u32 pos = 0;
+ u16 vsec_id;
+ u8 status;
+
+ while ((pos = pci_find_next_ext_capability(pdev, pos,
+ PCI_EXT_CAP_ID_VNDR))) {
+ pci_read_config_word(pdev, pos + 4, &vsec_id);
+#define FW_STATUS_VSEC_ID 0xA3
+ if (vsec_id != FW_STATUS_VSEC_ID)
+ continue;
+
+ pci_read_config_byte(pdev, (pos + 8), &status);
+ dev_info(&pdev->dev, "Firmware ready status = %u\n", status);
+ return status;
+ }
+ return false;
+}
+
/**
* octep_probe() - Octeon PCI device probe handler.
*
@@ -1051,6 +1071,12 @@ static int octep_probe(struct pci_dev *pdev, const struct pci_device_id *ent)

pci_set_master(pdev);

+ if (!get_fw_ready_status(pdev)) {
+ dev_notice(&pdev->dev, "Firmware not ready; defer probe.\n");
+ err = -EPROBE_DEFER;
+ goto err_alloc_netdev;
+ }
+
netdev = alloc_etherdev_mq(sizeof(struct octep_device),
OCTEP_MAX_QUEUES);
if (!netdev) {
--
2.36.0