Enable MSI support in sdhci-pci driver and provide the mechanism
to fall back to Legacy Pin-based Interrupt if MSI register fails.
That is, sdhci-pci driver first checks and enables MSI. If error occurs,
it will fall to use Legacy Pin-based Interrupt.
Tested with SD cards on AMD platform.
Signed-off-by: Jackey Shen <Jackey.Shen@xxxxxxx>
---
This patch is based on the patches e6039832 and 210b7d28 and applies to
the mmc-next branch.
NOTE:
If SD host controllers support and enable PCI MSI successfully, but doesn't
function well, the kind of patch like patch 210b7d28 should be added.
V4:
- update host->irq right after enabling MSI successfully or not
V3:
- clarify and tidy source code logic
- export sdhci_irq function to be used in sdhci-pci driver
V2:
- implement this PCI MSI feature in sdhci-pci.c instead of sdhci.c
---
drivers/mmc/host/sdhci-pci.c | 56 ++++++++++++++++++++++++++++++++++++++++++--
drivers/mmc/host/sdhci.c | 27 ++++++++++++---------
drivers/mmc/host/sdhci.h | 1 +
include/linux/mmc/sdhci.h | 2 ++
4 files changed, 73 insertions(+), 13 deletions(-)
diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
index 8f75381..b9dd9bd 100644
--- a/drivers/mmc/host/sdhci-pci.c
+++ b/drivers/mmc/host/sdhci-pci.c
@@ -1143,6 +1143,48 @@ static void sdhci_pci_hw_reset(struct sdhci_host *host)
slot->hw_reset(host);
}
+static int sdhci_pci_enable_msi(struct sdhci_host *host)
+{
+ int ret;
+ struct pci_dev *pdev = to_pci_dev(host->mmc->parent);
+
+ if (!host->msi_enabled) {
+ ret = pci_enable_msi(pdev);
+ if (ret) {
+ dev_warn(&pdev->dev, "Fail to allocate MSI entry\n");
+ host->irq = pdev->irq;
+ host->msi_enabled = false;
+ return ret;
+ }
+ }
+
+ ret = request_irq(pdev->irq, sdhci_irq, 0,
+ mmc_hostname(host->mmc), host);
+ if (ret) {
+ dev_warn(&pdev->dev, "Fail to request MSI IRQ %d: %d\n",
+ pdev->irq, ret);
+ pci_disable_msi(pdev);
+ host->irq = pdev->irq;
+ host->msi_enabled = false;
+ return ret;
+ }
+
+ host->irq = pdev->irq;
+ host->msi_enabled = true;
+ return ret;
+}
+
+static void sdhci_pci_disable_msi(struct sdhci_host *host)
+{
+ struct pci_dev *pdev = to_pci_dev(host->mmc->parent);
+
+ if (host->msi_enabled) {
+ pci_disable_msi(pdev);
+ host->irq = pdev->irq;
+ host->msi_enabled = false;
+ }
+}
+
static const struct sdhci_ops sdhci_pci_ops = {
.enable_dma = sdhci_pci_enable_dma,
.platform_bus_width = sdhci_pci_bus_width,
@@ -1242,6 +1284,10 @@ static int sdhci_pci_resume(struct device *dev)
if (!slot)
continue;
+ ret = sdhci_pci_enable_msi(slot->host);
+ if (ret)
+ dev_warn(&pdev->dev, "Fall back to Pin-based Interrupt: %d\n", ret);
+
ret = sdhci_resume_host(slot->host);
if (ret)
return ret;
@@ -1415,8 +1461,6 @@ static struct sdhci_pci_slot *sdhci_pci_probe_slot(
host->quirks = chip->quirks;
host->quirks2 = chip->quirks2;
- host->irq = pdev->irq;
-
ret = pci_request_region(pdev, bar, mmc_hostname(host->mmc));
if (ret) {
dev_err(&pdev->dev, "cannot request region\n");
@@ -1436,6 +1480,10 @@ static struct sdhci_pci_slot *sdhci_pci_probe_slot(
goto unmap;
}
+ ret = sdhci_pci_enable_msi(host);
+ if (ret)
+ dev_warn(&pdev->dev, "Fall back to Pin-based Interrupt: %d\n", ret);
+
if (gpio_is_valid(slot->rst_n_gpio)) {
if (!gpio_request(slot->rst_n_gpio, "eMMC_reset")) {
gpio_direction_output(slot->rst_n_gpio, 1);
@@ -1463,6 +1511,8 @@ remove:
if (gpio_is_valid(slot->rst_n_gpio))
gpio_free(slot->rst_n_gpio);
+ sdhci_pci_disable_msi(host);
+
if (chip->fixes && chip->fixes->remove_slot)
chip->fixes->remove_slot(slot, 0);
@@ -1499,6 +1549,8 @@ static void sdhci_pci_remove_slot(struct sdhci_pci_slot *slot)
if (gpio_is_valid(slot->rst_n_gpio))
gpio_free(slot->rst_n_gpio);
+ sdhci_pci_disable_msi(slot->host);
+
if (slot->chip->fixes && slot->chip->fixes->remove_slot)
slot->chip->fixes->remove_slot(slot, dead);
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index bd8a098..bd64825 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2412,7 +2412,7 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
}
}
-static irqreturn_t sdhci_irq(int irq, void *dev_id)
+irqreturn_t sdhci_irq(int irq, void *dev_id)
{
irqreturn_t result;
struct sdhci_host *host = dev_id;
@@ -2527,6 +2527,7 @@ out:
return result;
}
+EXPORT_SYMBOL_GPL(sdhci_irq);
/*****************************************************************************\
* *
@@ -2597,10 +2598,12 @@ int sdhci_resume_host(struct sdhci_host *host)
}
if (!device_may_wakeup(mmc_dev(host->mmc))) {
- ret = request_irq(host->irq, sdhci_irq, IRQF_SHARED,
- mmc_hostname(host->mmc), host);
- if (ret)
- return ret;
+ if (!host->msi_enabled) {
+ ret = request_irq(host->irq, sdhci_irq, IRQF_SHARED,
+ mmc_hostname(host->mmc), host);
+ if (ret)
+ return ret;
+ }
} else {
sdhci_disable_irq_wakeups(host);
disable_irq_wake(host->irq);
@@ -3220,12 +3223,14 @@ int sdhci_add_host(struct sdhci_host *host)
sdhci_init(host, 0);
- ret = request_irq(host->irq, sdhci_irq, IRQF_SHARED,
- mmc_hostname(mmc), host);
- if (ret) {
- pr_err("%s: Failed to request IRQ %d: %d\n",
- mmc_hostname(mmc), host->irq, ret);
- goto untasklet;
+ if (!host->msi_enabled) {
+ ret = request_irq(host->irq, sdhci_irq, IRQF_SHARED,
+ mmc_hostname(host->mmc), host);
+ if (ret) {
+ pr_err("%s: Failed to request IRQ %d: %d\n",
+ mmc_hostname(mmc), host->irq, ret);
+ goto untasklet;
+ }
}
#ifdef CONFIG_MMC_DEBUG
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 0a3ed01..597e53d 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -396,6 +396,7 @@ extern int sdhci_add_host(struct sdhci_host *host);
extern void sdhci_remove_host(struct sdhci_host *host, int dead);
extern void sdhci_send_command(struct sdhci_host *host,
struct mmc_command *cmd);
+extern irqreturn_t sdhci_irq(int irq, void *dev_id);
#ifdef CONFIG_PM
extern int sdhci_suspend_host(struct sdhci_host *host);
diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
index 3e781b8..e36b74f 100644
--- a/include/linux/mmc/sdhci.h
+++ b/include/linux/mmc/sdhci.h
@@ -99,6 +99,8 @@ struct sdhci_host {
/* Controller has a non-standard host control register */
#define SDHCI_QUIRK2_BROKEN_HOST_CONTROL (1<<5)
+ bool msi_enabled; /* PCI MSI is enabled or not */
+
int irq; /* Device IRQ */
void __iomem *ioaddr; /* Mapped address */
--
1.8.1.2
--
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