[PATCH 3.16 168/254] sh_eth: fix TSU resource handling

Ben Hutchings
2018-02-28T16:35:30Z

From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

commit dfe8266b8dd10e12a731c985b725fcf7f0e537f0 upstream.

When switching the driver to the managed device API, I managed to break
the case of a dual Ether devices sharing a single TSU: the 2nd Ether port
wouldn't probe. Iwamatsu-san has tried to fix this but his patch was buggy
and he then dropped the ball...

The solution is to limit calling devm_request_mem_region() to the first
of the two ports sharing the same TSU, so devm_ioremap_resource() can't
be used anymore for the TSU resource...

Fixes: d5e07e69218f ("sh_eth: use managed device API")
Reported-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/net/ethernet/renesas/sh_eth.c | 25 ++++++++++++++++++++++---
1 file changed, 22 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -2873,10 +2873,29 @@ static int sh_eth_drv_probe(struct platf
/* ioremap the TSU registers */
if (mdp->cd->tsu) {
struct resource *rtsu;
+
rtsu = platform_get_resource(pdev, IORESOURCE_MEM, 1);
- mdp->tsu_addr = devm_ioremap_resource(&pdev->dev, rtsu);
- if (IS_ERR(mdp->tsu_addr)) {
- ret = PTR_ERR(mdp->tsu_addr);
+ if (!rtsu) {
+ dev_err(&pdev->dev, "no TSU resource\n");
+ ret = -ENODEV;
+ goto out_release;
+ }
+ /* We can only request the TSU region for the first port
+ * of the two sharing this TSU for the probe to succeed...
+ */
+ if (devno % 2 == 0 &&
+ !devm_request_mem_region(&pdev->dev, rtsu->start,
+ resource_size(rtsu),
+ dev_name(&pdev->dev))) {
+ dev_err(&pdev->dev, "can't request TSU resource.\n");
+ ret = -EBUSY;
+ goto out_release;
+ }
+ mdp->tsu_addr = devm_ioremap(&pdev->dev, rtsu->start,
+ resource_size(rtsu));
+ if (!mdp->tsu_addr) {
+ dev_err(&pdev->dev, "TSU region ioremap() failed.\n");
+ ret = -ENOMEM;
goto out_release;
}
mdp->port = devno % 2;