Re: [PATCH] Add MSI support for SDHCI PCI hosts

From: Aaron Lu
Date: Mon Aug 20 2012 - 01:25:15 EST

Next message: Arnd Bergmann: "Re: [PATCH] leds-lm3530: replace pwm platform functions with generic pwm functions"
Previous message: Yanmin Zhang: "Re: [PATCH] x86/fixup_irq: using the cpu_online_mask instead ofcpu_all_mask"
In reply to: Daniel J Blueman: "Re: [PATCH] Add MSI support for SDHCI PCI hosts"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

Hello,

On 08/18/2012 01:06 PM, Daniel J Blueman wrote:
> Hi Philip,
>
> The interrupt could be from another source, though Message Signalled
> Interrupts are a PCI (and variants) only feature at present. I'm happy
> to split the patch and/or make the module param specific to sdhci-pci.

Not sure if you are aware of the following thread:
http://marc.info/?l=linux-mmc&m=133346937412708&w=2

Enabling msi will break some systems.

And more comments below.

>
> Let's see what the maintainers prefer...Chris?
>
> Dan
>
> On 18 August 2012 00:35, Philip Rakity <prakity@xxxxxxxxxxx> wrote:
>>
>> The interrupt source could be from a non-pci device. Say a gpio or whatever.
>> Does it make sense to break this patch into two patches ?
>>
>> On Aug 17, 2012, at 2:14 AM, Daniel J Blueman <daniel@xxxxxxxxx> wrote:
>>
>>> Allow module parameter 'enable_msi' to request an MSI interrupt for
>>> hosts where available (presently PCI). Useful as a workaround on
>>> platforms where the legacy interrupt is broken.
>>>
>>> Signed-off-by: Daniel J Blueman <daniel@xxxxxxxxx>
>>> ---
>>> drivers/mmc/host/sdhci-pci.c | 30 ++++++++++++++++++++++++++++++
>>> drivers/mmc/host/sdhci.c | 23 +++++++++++++++++++++++
>>> drivers/mmc/host/sdhci.h | 2 ++
>>> 3 files changed, 55 insertions(+)
>>>
>>> diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
>>> index 504da71..fbde589 100644
>>> --- a/drivers/mmc/host/sdhci-pci.c
>>> +++ b/drivers/mmc/host/sdhci-pci.c
>>> @@ -934,6 +934,34 @@ static int sdhci_pci_enable_dma(struct sdhci_host *host)
>>> return 0;
>>> }
>>>
>>> +static int sdhci_pci_enable_msi(struct sdhci_host *host)
>>> +{
>>> + struct sdhci_pci_slot *slot;
>>> + struct pci_dev *pdev;
>>> + int ret;
>>> +
>>> + slot = sdhci_priv(host);
>>> + pdev = slot->chip->pdev;
>>> +
>>> + ret = pci_enable_msi(pdev);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + host->irq = pdev->irq;
>>> + return 0;
>>> +}
>>> +
>>> +static void sdhci_pci_disable_msi(struct sdhci_host *host)
>>> +{
>>> + struct sdhci_pci_slot *slot;
>>> + struct pci_dev *pdev;
>>> +
>>> + slot = sdhci_priv(host);
>>> + pdev = slot->chip->pdev;
>>> +
>>> + pci_disable_msi(pdev);
>>> +}
>>> +
>>> static int sdhci_pci_8bit_width(struct sdhci_host *host, int width)
>>> {
>>> u8 ctrl;
>>> @@ -976,6 +1004,8 @@ static void sdhci_pci_hw_reset(struct sdhci_host *host)
>>>
>>> static struct sdhci_ops sdhci_pci_ops = {
>>> .enable_dma = sdhci_pci_enable_dma,
>>> + .enable_msi = sdhci_pci_enable_msi,
>>> + .disable_msi = sdhci_pci_disable_msi,
>>> .platform_8bit_width = sdhci_pci_8bit_width,
>>> .hw_reset = sdhci_pci_hw_reset,
>>> };
>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>> index 9a11dc3..9fa2180 100644
>>> --- a/drivers/mmc/host/sdhci.c
>>> +++ b/drivers/mmc/host/sdhci.c
>>> @@ -45,6 +45,7 @@
>>>
>>> static unsigned int debug_quirks = 0;
>>> static unsigned int debug_quirks2;
>>> +static bool enable_msi;
>>>
>>> static void sdhci_finish_data(struct sdhci_host *);
>>>
>>> @@ -2433,6 +2434,9 @@ int sdhci_suspend_host(struct sdhci_host *host)
>>>
>>> free_irq(host->irq, host);
>>>
>>> + if (host->ops->disable_msi && enable_msi)
>>> + host->ops->disable_msi(host);
>>> +

Don't know why msi needs to be disabled/enabled on suspend/resume.
And doing this in sdhci_pci_suspend/resume might be more appropriate if
required.

Thanks,
Aaron

>>> return ret;
>>> }
>>>
>>> @@ -2447,6 +2451,12 @@ int sdhci_resume_host(struct sdhci_host *host)
>>> host->ops->enable_dma(host);
>>> }
>>>
>>> + if (host->ops->enable_msi && enable_msi) {
>>> + ret = host->ops->enable_msi(host);
>>> + if (ret)
>>> + return ret;
>>> + }
>>> +
>>> ret = request_irq(host->irq, sdhci_irq, IRQF_SHARED,
>>> mmc_hostname(host->mmc), host);
>>> if (ret)
>>> @@ -3024,6 +3034,12 @@ int sdhci_add_host(struct sdhci_host *host)
>>> host->tuning_timer.function = sdhci_tuning_timer;
>>> }
>>>
>>> + if (host->ops->enable_msi && enable_msi) {
>>> + ret = host->ops->enable_msi(host);
>>> + if (ret)
>>> + return ret;
>>> + }
>>> +
>>> ret = request_irq(host->irq, sdhci_irq, IRQF_SHARED,
>>> mmc_hostname(mmc), host);
>>> if (ret) {
>>> @@ -3071,6 +3087,8 @@ int sdhci_add_host(struct sdhci_host *host)
>>> reset:
>>> sdhci_reset(host, SDHCI_RESET_ALL);
>>> free_irq(host->irq, host);
>>> + if (host->ops->disable_msi && enable_msi)
>>> + host->ops->disable_msi(host);
>>> #endif
>>> untasklet:
>>> tasklet_kill(&host->card_tasklet);
>>> @@ -3114,6 +3132,9 @@ void sdhci_remove_host(struct sdhci_host *host, int dead)
>>>
>>> free_irq(host->irq, host);
>>>
>>> + if (host->ops->disable_msi && enable_msi)
>>> + host->ops->disable_msi(host);
>>> +
>>> del_timer_sync(&host->timer);
>>>
>>> tasklet_kill(&host->card_tasklet);
>>> @@ -3162,6 +3183,7 @@ module_exit(sdhci_drv_exit);
>>>
>>> module_param(debug_quirks, uint, 0444);
>>> module_param(debug_quirks2, uint, 0444);
>>> +module_param(enable_msi, bool, 0444);
>>>
>>> MODULE_AUTHOR("Pierre Ossman <pierre@xxxxxxxxx>");
>>> MODULE_DESCRIPTION("Secure Digital Host Controller Interface core driver");
>>> @@ -3169,3 +3191,4 @@ MODULE_LICENSE("GPL");
>>>
>>> MODULE_PARM_DESC(debug_quirks, "Force certain quirks.");
>>> MODULE_PARM_DESC(debug_quirks2, "Force certain other quirks.");
>>> +MODULE_PARM_DESC(debug_quirks2, "Enable MSI interrupt support where possible.");
>>> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
>>> index 97653ea..df4e003 100644
>>> --- a/drivers/mmc/host/sdhci.h
>>> +++ b/drivers/mmc/host/sdhci.h
>>> @@ -264,6 +264,8 @@ struct sdhci_ops {
>>> void (*set_clock)(struct sdhci_host *host, unsigned int clock);
>>>
>>> int (*enable_dma)(struct sdhci_host *host);
>>> + int (*enable_msi)(struct sdhci_host *host);
>>> + void (*disable_msi)(struct sdhci_host *host);
>>> unsigned int (*get_max_clock)(struct sdhci_host *host);
>>> unsigned int (*get_min_clock)(struct sdhci_host *host);
>>> unsigned int (*get_timeout_clock)(struct sdhci_host *host);
>>> --
>>> 1.7.10.4
>>>
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
>>> the body of a message to majordomo@xxxxxxxxxxxxxxx
>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>
>
>
>

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

Next message: Arnd Bergmann: "Re: [PATCH] leds-lm3530: replace pwm platform functions with generic pwm functions"
Previous message: Yanmin Zhang: "Re: [PATCH] x86/fixup_irq: using the cpu_online_mask instead ofcpu_all_mask"
In reply to: Daniel J Blueman: "Re: [PATCH] Add MSI support for SDHCI PCI hosts"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]