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ata: ahci_brcm: Fix AHCI resources management

The AHCI resources management within ahci_brcm.c is a little convoluted, largely because it historically had a dedicated clock that was managed within this file in the downstream tree. Once brough upstream though, the clock was left to be managed by libahci_platform.c which is entirely appropriate. This patch series ensures that the AHCI resources are fetched and enabled before any register access is done, thus avoiding bus errors on platforms which clock gate the controller by default. As a result we need to re-arrange the suspend() and resume() functions in order to avoid accessing registers after the clocks have been turned off respectively before the clocks have been turned on. Finally, we can refactor brcm_ahci_get_portmask() in order to fetch the number of ports from hpriv->mmio which is now accessible without jumping through hoops like we used to do. The commit pointed in the Fixes tag is both old and new enough not to require major headaches for backporting of this patch.

Florian Fainelli committed 6 years ago

Commit c0cdf2a1 parent 84b032d1 file · +76 −29Browse files

Unified · Split

drivers/ata/ahci_brcm.c+76−29
@@ -213,19 +213,12 @@ static void brcm_sata_phys_disable(struct brcm_ahci_priv *priv) · 212 unmodified lines
213213 brcm_sata_phy_disable(priv, i);
214214 }
215215
216−static u32 brcm_ahci_get_portmask(struct platform_device *pdev,
216+static u32 brcm_ahci_get_portmask(struct ahci_host_priv *hpriv,
217217 struct brcm_ahci_priv *priv)
218218 {
219− void __iomem *ahci;
220− struct resource *res;
221219 u32 impl;
222220
223− res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ahci");
224− ahci = devm_ioremap_resource(&pdev->dev, res);
225− if (IS_ERR(ahci))
226− return 0;
227−
228− impl = readl(ahci + HOST_PORTS_IMPL);
221+ impl = readl(hpriv->mmio + HOST_PORTS_IMPL);
229222
230223 if (fls(impl) > SATA_TOP_MAX_PHYS)
231224 dev_warn(priv->dev, "warning: more ports than PHYs (%#x)\n",
@@ -233,9 +226,6 @@ static u32 brcm_ahci_get_portmask(struct platform_device *pdev, · 1 unmodified line
233226 else if (!impl)
234227 dev_info(priv->dev, "no ports found\n");
235228
236− devm_iounmap(&pdev->dev, ahci);
237− devm_release_mem_region(&pdev->dev, res->start, resource_size(res));
238−
239229 return impl;
240230 }
241231
@@ -347,11 +337,10 @@ static int brcm_ahci_suspend(struct device *dev) · 105 unmodified lines
347337 struct ata_host *host = dev_get_drvdata(dev);
348338 struct ahci_host_priv *hpriv = host->private_data;
349339 struct brcm_ahci_priv *priv = hpriv->plat_data;
350− int ret;
351340
352− ret = ahci_platform_suspend(dev);
353341 brcm_sata_phys_disable(priv);
354− return ret;
342+
343+ return ahci_platform_suspend(dev);
355344 }
356345
357346 static int brcm_ahci_resume(struct device *dev)
@@ -359,11 +348,44 @@ static int brcm_ahci_resume(struct device *dev) · 1 unmodified line
359348 struct ata_host *host = dev_get_drvdata(dev);
360349 struct ahci_host_priv *hpriv = host->private_data;
361350 struct brcm_ahci_priv *priv = hpriv->plat_data;
351+ int ret;
352+
353+ /* Make sure clocks are turned on before re-configuration */
354+ ret = ahci_platform_enable_clks(hpriv);
355+ if (ret)
356+ return ret;
362357
363358 brcm_sata_init(priv);
364359 brcm_sata_phys_enable(priv);
365360 brcm_sata_alpm_init(hpriv);
366− return ahci_platform_resume(dev);
361+
362+ /* Since we had to enable clocks earlier on, we cannot use
363+ * ahci_platform_resume() as-is since a second call to
364+ * ahci_platform_enable_resources() would bump up the resources
365+ * (regulators, clocks, PHYs) count artificially so we copy the part
366+ * after ahci_platform_enable_resources().
367+ */
368+ ret = ahci_platform_enable_phys(hpriv);
369+ if (ret)
370+ goto out_disable_phys;
371+
372+ ret = ahci_platform_resume_host(dev);
373+ if (ret)
374+ goto out_disable_platform_phys;
375+
376+ /* We resumed so update PM runtime state */
377+ pm_runtime_disable(dev);
378+ pm_runtime_set_active(dev);
379+ pm_runtime_enable(dev);
380+
381+ return 0;
382+
383+out_disable_platform_phys:
384+ ahci_platform_disable_phys(hpriv);
385+out_disable_phys:
386+ brcm_sata_phys_disable(priv);
387+ ahci_platform_disable_clks(hpriv);
388+ return ret;
367389 }
368390 #endif
369391
@@ -416,38 +438,63 @@ static int brcm_ahci_probe(struct platform_device *pdev) · 46 unmodified lines
416438 priv->quirks |= BRCM_AHCI_QUIRK_SKIP_PHY_ENABLE;
417439 }
418440
441+ hpriv = ahci_platform_get_resources(pdev, 0);
442+ if (IS_ERR(hpriv)) {
443+ ret = PTR_ERR(hpriv);
444+ goto out_reset;
445+ }
446+
447+ ret = ahci_platform_enable_clks(hpriv);
448+ if (ret)
449+ goto out_reset;
450+
451+ /* Must be first so as to configure endianness including that
452+ * of the standard AHCI register space.
453+ */
419454 brcm_sata_init(priv);
420455
421− priv->port_mask = brcm_ahci_get_portmask(pdev, priv);
422− if (!priv->port_mask)
423− return -ENODEV;
456+ /* Initializes priv->port_mask which is used below */
457+ priv->port_mask = brcm_ahci_get_portmask(hpriv, priv);
458+ if (!priv->port_mask) {
459+ ret = -ENODEV;
460+ goto out_disable_clks;
461+ }
424462
463+ /* Must be done before ahci_platform_enable_phys() */
425464 brcm_sata_phys_enable(priv);
426465
427− hpriv = ahci_platform_get_resources(pdev, 0);
428− if (IS_ERR(hpriv))
429− return PTR_ERR(hpriv);
430466 hpriv->plat_data = priv;
431467 hpriv->flags = AHCI_HFLAG_WAKE_BEFORE_STOP;
432468
433469 brcm_sata_alpm_init(hpriv);
434470
435− ret = ahci_platform_enable_resources(hpriv);
436− if (ret)
437− return ret;
438−
439471 if (priv->quirks & BRCM_AHCI_QUIRK_NO_NCQ)
440472 hpriv->flags |= AHCI_HFLAG_NO_NCQ;
441473 hpriv->flags |= AHCI_HFLAG_NO_WRITE_TO_RO;
442474
475+ ret = ahci_platform_enable_phys(hpriv);
476+ if (ret)
477+ goto out_disable_phys;
478+
443479 ret = ahci_platform_init_host(pdev, hpriv, &ahci_brcm_port_info,
444480 &ahci_platform_sht);
445481 if (ret)
446− return ret;
482+ goto out_disable_platform_phys;
447483
448484 dev_info(dev, "Broadcom AHCI SATA3 registered\n");
449485
450486 return 0;
487+
488+out_disable_platform_phys:
489+ ahci_platform_disable_phys(hpriv);
490+out_disable_phys:
491+ brcm_sata_phys_disable(priv);
492+out_disable_clks:
493+ ahci_platform_disable_clks(hpriv);
494+out_reset:
495+ if (!IS_ERR_OR_NULL(priv->rcdev))
496+ reset_control_assert(priv->rcdev);
497+ return ret;
451498 }
452499
453500 static int brcm_ahci_remove(struct platform_device *pdev)
@@ -457,12 +504,12 @@ static int brcm_ahci_remove(struct platform_device *pdev) · 3 unmodified lines
457504 struct brcm_ahci_priv *priv = hpriv->plat_data;
458505 int ret;
459506
507+ brcm_sata_phys_disable(priv);
508+
460509 ret = ata_platform_remove_one(pdev);
461510 if (ret)
462511 return ret;
463512
464− brcm_sata_phys_disable(priv);
465−
466513 return 0;
467514 }
468515