From: Niklas Neronin Date: Thu, 15 May 2025 13:56:14 +0000 (+0300) Subject: usb: xhci: remove '0' write to write-1-to-clear register X-Git-Tag: v6.16-rc1~28^2~40 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=e1db856bd28891d70008880d7f1d3b8d1ea948fd;p=linux-block.git usb: xhci: remove '0' write to write-1-to-clear register xHCI specification 1.2, section 5.5.2.1. Interrupt Pending bit is RW1C (Write-1-to-clear), which means that writing '0' to is has no effect and is removed. The Interrupt Pending (IP) bit is cleared at the start of interrupt handling; xhci_clear_interrupt_pending(). This could theoretically cause a new interrupt to be issued before the xhci driver reaches the interrupter disable functions. To address this, the IP bit is read after Interrupt Enable is disabled, and a debug message is issued if the IP bit is still set. Signed-off-by: Niklas Neronin Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20250515135621.335595-18-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c index 486347776cb2..92bb84f8132a 100644 --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -1907,7 +1907,7 @@ int xhci_bus_resume(struct usb_hcd *hcd) * prevent port event interrupts from interfering * with usb2 port resume process */ - xhci_disable_interrupter(xhci->interrupters[0]); + xhci_disable_interrupter(xhci, xhci->interrupters[0]); disabled_irq = true; } } diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 4a4410f7978f..1cae4ec6c7e9 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -3166,7 +3166,7 @@ void xhci_skip_sec_intr_events(struct xhci_hcd *xhci, dma_addr_t deq; /* disable irq, ack pending interrupt and ack all pending events */ - xhci_disable_interrupter(ir); + xhci_disable_interrupter(xhci, ir); /* last acked event trb is in erdp reg */ erdp_reg = xhci_read_64(xhci, &ir->ir_set->erst_dequeue); diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 8cdb1a01a3ed..6c4bbabc3a70 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -331,7 +331,6 @@ int xhci_enable_interrupter(struct xhci_interrupter *ir) return -EINVAL; iman = readl(&ir->ir_set->irq_pending); - iman &= ~IMAN_IP; iman |= IMAN_IE; writel(iman, &ir->ir_set->irq_pending); @@ -340,7 +339,7 @@ int xhci_enable_interrupter(struct xhci_interrupter *ir) return 0; } -int xhci_disable_interrupter(struct xhci_interrupter *ir) +int xhci_disable_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir) { u32 iman; @@ -348,11 +347,13 @@ int xhci_disable_interrupter(struct xhci_interrupter *ir) return -EINVAL; iman = readl(&ir->ir_set->irq_pending); - iman &= ~IMAN_IP; iman &= ~IMAN_IE; writel(iman, &ir->ir_set->irq_pending); - readl(&ir->ir_set->irq_pending); + iman = readl(&ir->ir_set->irq_pending); + if (iman & IMAN_IP) + xhci_dbg(xhci, "%s: Interrupt pending\n", __func__); + return 0; } @@ -754,7 +755,7 @@ void xhci_stop(struct usb_hcd *hcd) "// Disabling event ring interrupts"); temp = readl(&xhci->op_regs->status); writel((temp & ~0x1fff) | STS_EINT, &xhci->op_regs->status); - xhci_disable_interrupter(ir); + xhci_disable_interrupter(xhci, ir); xhci_dbg_trace(xhci, trace_xhci_dbg_init, "cleaning up memory"); xhci_mem_cleanup(xhci); @@ -1189,7 +1190,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool power_lost, bool is_auto_resume) xhci_dbg(xhci, "// Disabling event ring interrupts\n"); temp = readl(&xhci->op_regs->status); writel((temp & ~0x1fff) | STS_EINT, &xhci->op_regs->status); - xhci_disable_interrupter(xhci->interrupters[0]); + xhci_disable_interrupter(xhci, xhci->interrupters[0]); xhci_dbg(xhci, "cleaning up memory\n"); xhci_mem_cleanup(xhci); diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 28c4ad7534c1..fc6b97add7fa 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1900,7 +1900,7 @@ int xhci_alloc_tt_info(struct xhci_hcd *xhci, int xhci_set_interrupter_moderation(struct xhci_interrupter *ir, u32 imod_interval); int xhci_enable_interrupter(struct xhci_interrupter *ir); -int xhci_disable_interrupter(struct xhci_interrupter *ir); +int xhci_disable_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir); /* xHCI ring, segment, TRB, and TD functions */ dma_addr_t xhci_trb_virt_to_dma(struct xhci_segment *seg, union xhci_trb *trb);