| Message ID | 20201025221735.3062-33-digetx@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Introduce memory interconnect for NVIDIA Tegra SoCs | expand |
On Mon, Oct 26, 2020 at 01:17:15AM +0300, Dmitry Osipenko wrote: > EMC driver will become mandatory after turning it into interconnect > provider because interconnect users, like display controller driver, will > fail to probe using newer device-trees that have interconnect properties. > Thus make EMC driver to probe even if timings are missing in device-tree. Does it really have to be mandatory? Sounds like that's going to make it unnecessarily complicated to merge all of this. Is it complicated to make interconnect support optional in consumer drivers? Thierry
27.10.2020 16:52, Thierry Reding пишет: > On Mon, Oct 26, 2020 at 01:17:15AM +0300, Dmitry Osipenko wrote: >> EMC driver will become mandatory after turning it into interconnect >> provider because interconnect users, like display controller driver, will >> fail to probe using newer device-trees that have interconnect properties. >> Thus make EMC driver to probe even if timings are missing in device-tree. > > Does it really have to be mandatory? Sounds like that's going to make it > unnecessarily complicated to merge all of this. Is it complicated to > make interconnect support optional in consumer drivers? Interconnect provider can't be optional if interconnect properties present in a device-tree because drivers that use ICC path will get -EPROBE_DEFER until ICC provider is registered. Older device-trees don't have ICC properties, and thus, the ICC users/consumers will get a dummy NULL ICC path in this case. I.e. ICC core handles this for us.
diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c index ce22ca7cfb77..34085e26dced 100644 --- a/drivers/memory/tegra/tegra20-emc.c +++ b/drivers/memory/tegra/tegra20-emc.c @@ -383,6 +383,11 @@ tegra_emc_find_node_by_ram_code(struct device *dev) u32 value, ram_code; int err; + if (of_get_child_count(dev->of_node) == 0) { + dev_info(dev, "device-tree doesn't have memory timings\n"); + return NULL; + } + if (!of_property_read_bool(dev->of_node, "nvidia,use-ram-code")) return of_node_get(dev->of_node); @@ -451,6 +456,9 @@ static long emc_round_rate(unsigned long rate, struct tegra_emc *emc = arg; unsigned int i; + if (!emc->num_timings) + return clk_get_rate(emc->clk); + min_rate = min(min_rate, emc->timings[emc->num_timings - 1].rate); for (i = 0; i < emc->num_timings; i++) { @@ -656,13 +664,6 @@ static int tegra_emc_probe(struct platform_device *pdev) struct tegra_emc *emc; int irq, err; - /* driver has nothing to do in a case of memory timing absence */ - if (of_get_child_count(pdev->dev.of_node) == 0) { - dev_info(&pdev->dev, - "EMC device tree node doesn't have memory timings\n"); - return 0; - } - irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(&pdev->dev, "interrupt not specified\n"); @@ -670,23 +671,20 @@ static int tegra_emc_probe(struct platform_device *pdev) return irq; } - np = tegra_emc_find_node_by_ram_code(&pdev->dev); - if (!np) - return -EINVAL; - emc = devm_kzalloc(&pdev->dev, sizeof(*emc), GFP_KERNEL); - if (!emc) { - of_node_put(np); + if (!emc) return -ENOMEM; - } emc->clk_nb.notifier_call = tegra_emc_clk_change_notify; emc->dev = &pdev->dev; - err = tegra_emc_load_timings_from_dt(emc, np); - of_node_put(np); - if (err) - return err; + np = tegra_emc_find_node_by_ram_code(&pdev->dev); + if (np) { + err = tegra_emc_load_timings_from_dt(emc, np); + of_node_put(np); + if (err) + return err; + } emc->regs = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(emc->regs))
EMC driver will become mandatory after turning it into interconnect provider because interconnect users, like display controller driver, will fail to probe using newer device-trees that have interconnect properties. Thus make EMC driver to probe even if timings are missing in device-tree. Signed-off-by: Dmitry Osipenko <digetx@gmail.com> --- drivers/memory/tegra/tegra20-emc.c | 34 ++++++++++++++---------------- 1 file changed, 16 insertions(+), 18 deletions(-)