Hi Russell, Yes, that needs to be taken care of. Hiroshi has suggested that we move this logic into the omap_mbox_get() function. Will add code to protect from races conditions while making the change. Thank you and Regards Subbu > -----Original Message----- > From: Russell King [mailto:rmk@xxxxxxxxxxxxxxxx] > Sent: Monday, September 07, 2009 8:35 PM > To: C.A, Subramaniam > Cc: linux-omap@xxxxxxxxxxxxxxx; tony@xxxxxxxxxxx; > Hiroshi.DOYU@xxxxxxxxx; Kanigeri, Hari; Gupta, Ramesh > Subject: Re: [PATCH 8/10] omap mailbox: OMAP4-Mailbox - Adds > code changes to support OMAP4 mailbox. > > On Fri, Sep 04, 2009 at 05:18:11PM +0530, C.A, Subramaniam wrote: > > @@ -70,31 +89,37 @@ static inline void mbox_write_reg(u32 > val, size_t > > ofs) static int omap2_mbox_startup(struct omap_mbox *mbox) { > > unsigned int l; > > + if (!mbox_configured) { > > + mbox_ick_handle = clk_get(NULL, "mailboxes_ick"); > > + if (IS_ERR(mbox_ick_handle)) { > > + printk(KERN_ERR "Could not get > mailboxes_ick\n"); > > + return -ENODEV; > > + } > > + clk_enable(mbox_ick_handle); > > > > - mbox_ick_handle = clk_get(NULL, "mailboxes_ick"); > > - if (IS_ERR(mbox_ick_handle)) { > > - printk("Could not get mailboxes_ick\n"); > > - return -ENODEV; > > - } > > - clk_enable(mbox_ick_handle); > > - > > - l = mbox_read_reg(MAILBOX_REVISION); > > - pr_info("omap mailbox rev %d.%d\n", (l & 0xf0) >> 4, (l > & 0x0f)); > > - > > - /* set smart-idle & autoidle */ > > - l = mbox_read_reg(MAILBOX_SYSCONFIG); > > - l |= 0x00000011; > > - mbox_write_reg(l, MAILBOX_SYSCONFIG); > > + l = mbox_read_reg(MAILBOX_REVISION); > > + pr_info("omap mailbox rev %d.%d\n", (l & 0xf0) >> 4, > > + (l & 0x0f)); > > > > + /* set smart-idle & autoidle */ > > + l = mbox_read_reg(MAILBOX_SYSCONFIG); > > + l |= 0x00000011; > > + mbox_write_reg(l, MAILBOX_SYSCONFIG); > > + } > > + mbox_configured++; > > I assume you're doing this because this function can be > called multiple times. What protects this against races? > > > omap2_mbox_enable_irq(mbox, IRQ_RX); > > > > return 0; > > } > > > > static void omap2_mbox_shutdown(struct omap_mbox *mbox) -{ > > - clk_disable(mbox_ick_handle); > > - clk_put(mbox_ick_handle); > > +{ if (mbox_configured > 0) > > + mbox_configured--; > > + if (!mbox_configured) { > > + clk_disable(mbox_ick_handle); > > + clk_put(mbox_ick_handle); > > + mbox_ick_handle = NULL; > > + } > > Same concern - what protects mbox_configured and the > associated code against races? > > -- > Russell King > Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ > maintainer of: > > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
