> -----Original Message----- > From: Nipun Gupta [mailto:nipun.gupta@xxxxxxx] > Sent: Monday, December 11, 2017 9:16 PM > To: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>; stuyoder@xxxxxxxxx; > Bharat Bhushan <bharat.bhushan@xxxxxxx>; gregkh@xxxxxxxxxxxxxxxxxxx; > cakturk@xxxxxxxxx; bretth256@xxxxxxxxx; arnd@xxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxx; Nipun Gupta > <nipun.gupta@xxxxxxx> > Subject: [RESEND PATCH 1/2 v2] staging: fsl-mc: Allocate IRQ's before > scanning DPRC objects > > Following is the current scenario when the devices are probed: > > FSL_MC Bus probe ---> dprc probe ---> dprc devices scan ---> > probe devices in DPRC container ---> allocate IRQ's > > In case the devices being probed in the DPRC container need the IRQ's; > probing of that device will fail. > > In current scenario the devices which need IRQ's such as DPIO gets deferred > because they aren't registered when first time the probing of these devices > is done in the dprc scan. > So they are probed once IRQ's have been allocated. > > In case where DPRC probing itself gets deferred, which does in case IOMMU > is enabled; all the devices in DPRC container gets probed before IRQ's are > allocated. This causes devices using IRQ's (such as DPIO) to fail. > > So having IRQ's allocated before any of the devices in the DPRC container are > probed is more legitimate. > > After this patch following is the flow of execution: > > FSL_MC Bus probe ---> dprc probe ---> dprc devices scan ---> > allocate IRQ's ---> probe of devices in DPRC container. > > Signed-off-by: Nipun Gupta <nipun.gupta@xxxxxxx> Looks ok to me, Reviewed-by: Bharat Bhushan <bharat.bhushan@xxxxxxx> > --- > Resending v2 as missed mentioning the changes in the version Changes in v2: > - Polished the commit message > - Minor updation in the comment added in the code 'Allocate IRQ's...' > > drivers/staging/fsl-mc/bus/dprc-driver.c | 49 ++++++++++++++++++--------- > ----- > 1 file changed, 27 insertions(+), 22 deletions(-) > > diff --git a/drivers/staging/fsl-mc/bus/dprc-driver.c b/drivers/staging/fsl- > mc/bus/dprc-driver.c > index 06df528..f4bde58 100644 > --- a/drivers/staging/fsl-mc/bus/dprc-driver.c > +++ b/drivers/staging/fsl-mc/bus/dprc-driver.c > @@ -206,7 +206,8 @@ static void dprc_add_new_devices(struct > fsl_mc_device *mc_bus_dev, > * dprc_scan_objects - Discover objects in a DPRC > * > * @mc_bus_dev: pointer to the fsl-mc device that represents a DPRC object > - * @total_irq_count: total number of IRQs needed by objects in the DPRC. > + * @total_irq_count: If argument is provided the function populates the > + * total number of IRQs created by objects in the DPRC. > * > * Detects objects added and removed from a DPRC and synchronizes the > * state of the Linux bus driver, MC by adding and removing @@ -228,6 > +229,7 @@ static int dprc_scan_objects(struct fsl_mc_device *mc_bus_dev, > int error; > unsigned int irq_count = mc_bus_dev->obj_desc.irq_count; > struct fsl_mc_obj_desc *child_obj_desc_array = NULL; > + struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev); > > error = dprc_get_obj_count(mc_bus_dev->mc_io, > 0, > @@ -297,7 +299,26 @@ static int dprc_scan_objects(struct fsl_mc_device > *mc_bus_dev, > } > } > > - *total_irq_count = irq_count; > + /* > + * Allocate IRQ's before binding the scanned devices with their > + * respective drivers. > + */ > + if (dev_get_msi_domain(&mc_bus_dev->dev) && !mc_bus- > >irq_resources) { > + if (irq_count > FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS) { > + dev_warn(&mc_bus_dev->dev, > + "IRQs needed (%u) exceed IRQs preallocated > (%u)\n", > + irq_count, > FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS); > + } > + > + error = fsl_mc_populate_irq_pool(mc_bus, > + FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS); > + if (error < 0) > + return error; > + } > + > + if (total_irq_count) > + *total_irq_count = irq_count; > + > dprc_remove_devices(mc_bus_dev, child_obj_desc_array, > num_child_objects); > > @@ -322,7 +343,6 @@ static int dprc_scan_objects(struct fsl_mc_device > *mc_bus_dev, static int dprc_scan_container(struct fsl_mc_device > *mc_bus_dev) { > int error; > - unsigned int irq_count; > struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev); > > fsl_mc_init_all_resource_pools(mc_bus_dev); > @@ -331,29 +351,14 @@ static int dprc_scan_container(struct fsl_mc_device > *mc_bus_dev) > * Discover objects in the DPRC: > */ > mutex_lock(&mc_bus->scan_mutex); > - error = dprc_scan_objects(mc_bus_dev, &irq_count); > + error = dprc_scan_objects(mc_bus_dev, NULL); > mutex_unlock(&mc_bus->scan_mutex); > - if (error < 0) > - goto error; > - > - if (dev_get_msi_domain(&mc_bus_dev->dev) && !mc_bus- > >irq_resources) { > - if (irq_count > FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS) { > - dev_warn(&mc_bus_dev->dev, > - "IRQs needed (%u) exceed IRQs preallocated > (%u)\n", > - irq_count, > FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS); > - } > - > - error = fsl_mc_populate_irq_pool( > - mc_bus, > - FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS); > - if (error < 0) > - goto error; > + if (error < 0) { > + fsl_mc_cleanup_all_resource_pools(mc_bus_dev); > + return error; > } > > return 0; > -error: > - fsl_mc_cleanup_all_resource_pools(mc_bus_dev); > - return error; > } > > /** > -- > 1.9.1 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
