On 11/08/2013 04:05 PM, Jackey Shen wrote:
> Hi Aaron,
> 
> On Fri, Nov 08, 2013 at 02:58:45PM +0800, Aaron Lu wrote:
>> On 11/01/2013 05:45 PM, Jackey Shen wrote:
>>> Enable MSI support in sdhci-pci driver and provide the mechanism
>>> to fall back to Legacy Pin-based Interrupt if MSI register fails.
>>>
>>> Signed-off-by: Jackey Shen <[email protected]>
>>> Reviewed-by: Huang Rui <[email protected]>
>>> ---
>>>  drivers/mmc/host/Kconfig  |  11 +++++
>>>  drivers/mmc/host/sdhci.c  | 108 
>>> ++++++++++++++++++++++++++++++++++++++++------
>>>  include/linux/mmc/sdhci.h |   2 +
>>>  3 files changed, 109 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
>>> index 7fc5099..a56cf27 100644
>>> --- a/drivers/mmc/host/Kconfig
>>> +++ b/drivers/mmc/host/Kconfig
>>> @@ -68,6 +68,17 @@ config MMC_SDHCI_PCI
>>>  
>>>       If unsure, say N.
>>>  
>>> +config MMC_SDHCI_PCI_MSI
>>> +   bool "SDHCI support with MSI on PCI bus"
>>> +   depends on MMC_SDHCI_PCI && PCI_MSI
>>> +   help
>>> +     This enables PCI MSI (Message Signaled Interrupts) for Secure
>>> +     Digital Host Controller Interface.
>>> +
>>> +     If you have a controller with this capability, say Y or M here.
>>> +
>>> +     If unsure, say N.
>>> +
>>>  config MMC_RICOH_MMC
>>>     bool "Ricoh MMC Controller Disabler"
>>>     depends on MMC_SDHCI_PCI
>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>> index 6785fb1..de509bc 100644
>>> --- a/drivers/mmc/host/sdhci.c
>>> +++ b/drivers/mmc/host/sdhci.c
>>
>> I think PCI stuffs should be in sdhci-pci.c, not sdhci.c.
> 
> But I ran into one issue as per your suggestion:
> sdhci_add|remove_host() in sdhci.c calls back sdhci_try_enable|cleanup()
> in_msi sdhci-pci.c if sdhci_try_enable|cleanup_msi() are moved into 
> sdhci-pci.c.

I don't know much about PCI and interrupt, but what is the problem of
doing enable/disable msi in sdhci_pci_probe_slot?

Thanks,
Aaron

> 
> Is it a best practice?
> 
> Thanks,
> Jackey
> 
>>
>> Thanks,
>> Aaron
>>
>>> @@ -13,6 +13,10 @@
>>>   *     - JMicron (hardware and technical support)
>>>   */
>>>  
>>> +#ifdef CONFIG_MMC_SDHCI_PCI_MSI
>>> +#include <linux/pci.h>
>>> +#endif
>>> +
>>>  #include <linux/delay.h>
>>>  #include <linux/highmem.h>
>>>  #include <linux/io.h>
>>> @@ -2520,6 +2524,64 @@ out:
>>>     return result;
>>>  }
>>>  
>>> +#ifdef CONFIG_MMC_SDHCI_PCI_MSI
>>> +static int sdhci_setup_msi(struct sdhci_host *host)
>>> +{
>>> +   int ret;
>>> +   struct pci_dev *pdev = to_pci_dev(host->mmc->parent);
>>> +
>>> +   host->msi_enabled = false;
>>> +
>>> +   ret = pci_enable_msi(pdev);
>>> +   if (ret) {
>>> +           pr_warn("%s: Failed to allocate MSI entry\n",
>>> +                   mmc_hostname(host->mmc));
>>> +           return ret;
>>> +   }
>>> +
>>> +   ret = request_irq(pdev->irq, sdhci_irq, 0,
>>> +           mmc_hostname(host->mmc), host);
>>> +   if (ret) {
>>> +           pr_warn("%s: Failed to request MSI IRQ %d: %d\n",
>>> +                  mmc_hostname(host->mmc), pdev->irq, ret);
>>> +           pci_disable_msi(pdev);
>>> +           return ret;
>>> +   }
>>> +
>>> +   host->irq = pdev->irq;
>>> +   host->msi_enabled = true;
>>> +   return ret;
>>> +}
>>> +
>>> +static int sdhci_try_enable_msi(struct sdhci_host *host)
>>> +{
>>> +   return sdhci_setup_msi(host);
>>> +}
>>> +
>>> +static void sdhci_cleanup_msi(struct sdhci_host *host)
>>> +{
>>> +   struct pci_dev *pdev = to_pci_dev(host->mmc->parent);
>>> +
>>> +   free_irq(host->irq, host);
>>> +   if (host->msi_enabled) {
>>> +           pci_disable_msi(pdev);
>>> +           host->msi_enabled = false;
>>> +   }
>>> +}
>>> +
>>> +#else
>>> +
>>> +static int sdhci_try_enable_msi(struct sdhci_host *host)
>>> +{
>>> +   return 0;
>>> +}
>>> +
>>> +static void sdhci_cleanup_msi(struct sdhci_host *host)
>>> +{
>>> +   free_irq(host->irq, host);
>>> +}
>>> +#endif /* CONFIG_MMC_SDHCI_PCI_MSI */
>>> +
>>>  
>>> /*****************************************************************************\
>>>   *                                                                         
>>>   *
>>>   * Suspend/resume                                                          
>>>   *
>>> @@ -2569,7 +2631,8 @@ int sdhci_suspend_host(struct sdhci_host *host)
>>>  
>>>     if (!device_may_wakeup(mmc_dev(host->mmc))) {
>>>             sdhci_mask_irqs(host, SDHCI_INT_ALL_MASK);
>>> -           free_irq(host->irq, host);
>>> +           /* free any IRQ and disable MSI */
>>> +           sdhci_cleanup_msi(host);
>>>     } else {
>>>             sdhci_enable_irq_wakeups(host);
>>>             enable_irq_wake(host->irq);
>>> @@ -2589,10 +2652,22 @@ 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);
>>> +           /* try to enable MSI */
>>> +           ret = sdhci_try_enable_msi(host);
>>>             if (ret)
>>> -                   return ret;
>>> +                   pr_warn("%s: Fall back to Legacy Pin-based Interrupt: 
>>> %d\n",
>>> +                           mmc_hostname(host->mmc), ret);
>>> +
>>> +           if (!host->msi_enabled) {
>>> +                   /* fall back to legacy pin-based interrupt */
>>> +                   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(host->mmc), host->irq, 
>>> ret);
>>> +                           return ret;
>>> +                   }
>>> +           }
>>>     } else {
>>>             sdhci_disable_irq_wakeups(host);
>>>             disable_irq_wake(host->irq);
>>> @@ -3212,12 +3287,21 @@ 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;
>>> +   /* try to enable MSI */
>>> +   ret = sdhci_try_enable_msi(host);
>>> +   if (ret)
>>> +           pr_warn("%s: Fall back to Legacy Pin-based Interrupt: %d\n",
>>> +                   mmc_hostname(host->mmc), ret);
>>> +
>>> +   if (!host->msi_enabled) {
>>> +           /* fall back to legacy pin-based interrupt */
>>> +           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(host->mmc), host->irq, ret);
>>> +                   goto untasklet;
>>> +           }
>>>     }
>>>  
>>>  #ifdef CONFIG_MMC_DEBUG
>>> @@ -3257,7 +3341,7 @@ int sdhci_add_host(struct sdhci_host *host)
>>>  reset:
>>>     sdhci_reset(host, SDHCI_RESET_ALL);
>>>     sdhci_mask_irqs(host, SDHCI_INT_ALL_MASK);
>>> -   free_irq(host->irq, host);
>>> +   sdhci_cleanup_msi(host);
>>>  #endif
>>>  untasklet:
>>>     tasklet_kill(&host->card_tasklet);
>>> @@ -3300,7 +3384,7 @@ void sdhci_remove_host(struct sdhci_host *host, int 
>>> dead)
>>>             sdhci_reset(host, SDHCI_RESET_ALL);
>>>  
>>>     sdhci_mask_irqs(host, SDHCI_INT_ALL_MASK);
>>> -   free_irq(host->irq, host);
>>> +   sdhci_cleanup_msi(host);
>>>  
>>>     del_timer_sync(&host->timer);
>>>  
>>> diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
>>> index 3e781b8..3812479 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;       /* SD host controller with PCI MSI enabled */
>>> +
>>>     int irq;                /* Device IRQ */
>>>     void __iomem *ioaddr;   /* Mapped address */
>>>  
>>>
>>
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